Disclosure of Invention
In order to improve the above problems, the present invention provides a compound represented by the following formula (a) or formula (B):
wherein X, Y, R are the same or different and independently represent H, F, Cl, Br, I, -NO2Unsubstituted or optionally substituted by one or more RaSubstituted of the following groups: c1-40Alkyl radical, C1-40Alkoxy radical, C3-20Cycloalkyl, 3-20 membered heterocyclyl, C6-20Aryl, 5-20 membered heteroaryl;
each RaIdentical or different, independently of one another, from the group-F, -Cl, -Br, -I, -OH, -SH, -CN, -NH2、=O、-NO2、-NH2Unsubstituted or optionally substituted by one or more RnSubstituted of the following groups: c1-40Alkyl radical, C1-40Alkyloxy, C1-40Alkylthio radical, C2-40Alkenyl radical, C2-40Alkenyloxy radical, C2-40Alkenylthio radical, C2-40Alkynyl, C2-40Alkynyloxy, C2-40Alkynylthio, C3-20Cycloalkyl radical, C3-20Cycloalkyl oxy, C3-20Cycloalkylthio, 3-20 membered heterocyclyl, 3-20 membered heterocyclyloxy, 3-20 membered heterocyclylthio, C6-20Aryl radical, C6-20Aryloxy radical, C6-20Arylthio, 5-20 membered heteroaryl, 5-20 membered heteroaryloxy, 5-20 membered heteroarylthio;
each RnIdentical or different, independently of one another, from the group consisting of H, -NH2、=O、C1-40Alkyl radical, C2-40Alkenyl radical, C2-40Alkynyl, C3-20Cycloalkyl, 3-20 membered heterocyclyl, C6-20Aryl, 5-20 membered heteroaryl.
According to an embodiment of the invention, said X, Y, R are the same or different and are independently selected from H, C1-40An alkyl group. Example (b)E.g., X, Y is selected from H and R is selected from CH3、C2H5、C3H7Or C4H9。
According to an embodiment of the invention, the compounds of formula (a) and (B) are each an axial chiral biphenyl ring-chain isomer, in particular an axial chiral biphenyl ring-chain tautomer.
The invention also provides a preparation method of the compound shown in the formula (A) or the formula (B), which comprises the steps of reacting the compound shown in the formula (I) with the compound shown in the formula (II) to obtain the compound shown in the formula (A) or the formula (B);
wherein X, Y, R has the definitions described above.
According to the invention, the reaction can be carried out under an inert gas blanket, such as a nitrogen blanket;
the reaction may be carried out in the presence of a tetradentate palladium catalyst, which may be Pd (PPh)3)4;
The reaction may further be carried out in the presence of a base and/or fluoride; wherein the base may be a salt of an alkali metal, for example a carbonate of an alkali metal, such as Cs2CO3、K2CO3、Na2CO3、Li2CO3One or more of; the fluoride can be one or more of tetrabutylammonium fluoride, cesium fluoride and potassium fluoride;
the molar ratio of the compound of formula (I) to the compound of formula (II) may be 1 (1-3), preferably 1 (1.5-2.5), for example 1: 2;
the molar ratio of the catalyst to the compound of formula (I) may be (0.03-0.07):1, preferably (0.04-0.06):1, for example 0.05: 1;
the molar ratio of the base and/or fluoride to the compound of formula (I) may be (1-5) to 1, preferably (2-4) to 1, for example 3: 1;
the reaction may be carried out in a solvent, and the solvent for the reaction may be a mixed solvent of an ether solvent and water, for example, a mixed solvent of 1, 4-dioxane and water;
the temperature of the reaction may be from 25 to 100 ℃, preferably from 60 to 100 ℃, for example 80 ℃;
the reaction time may be 6 to 24 hours, preferably 18 to 24 hours.
According to the invention, the preparation method further comprises the following steps:
1) reacting the compound of the formula (III) with thionyl chloride to obtain a compound of a formula (IV);
2) compounds of formula (IV) and RNH2Reacting to obtain a compound shown in a formula (I);
wherein X, R has the definitions described above.
According to the present invention, in step 1),
the reaction time may be 4 to 8 hours, preferably 5 to 7 hours, for example 6 hours.
The reaction may be carried out under heating, for example under reflux.
According to the present invention, in step 2),
the reaction may be carried out with the addition of a base, which may be an inorganic base such as sodium carbonate;
the molar ratio of the compound of formula (IV) to the base may be 1 (1-5), preferably 1 (2-4), for example 1: 3;
the reaction time may be 1 to 3 hours, for example 2 hours.
The reaction may be carried out in a solvent, which may be a halogenated hydrocarbon solvent, such as dichloromethane.
The invention also provides application of the axial chiral biphenyl compound, and the axial chiral biphenyl compound can be used for measuring the optical purity of the chiral compound.
According to the invention, the chiral compound may be a chiral alcohol, a chiral amine;
according to the invention, the chiral amine may be a chiral primary or a chiral secondary amine; the chiral amine is for example selected from 1-phenylethylamine, chiral 2- (methoxymethyl) pyrrolidine.
According to the invention, the chiral alcohol may be a chiral compound containing hydroxyl groups, such as chiral 3, 3-dimethyl-2-butanol, 3-methyl-2-butanol, menthol, 1-phenylethanol, methyl mandelate.
The present invention also provides a method for determining optical purity of a chiral compound, using the above axial chiral biphenyl compound, the method comprising the steps of:
(1) preparing an axial chiral biphenyl compound solution;
(2) adding a series of chiral compound solutions with known optical purity into the axial chiral biphenyl compound solution prepared in the step (1) for reaction, detecting a signal of the obtained product through a Circular Dichroism (CD), and establishing a calibration curve, namely establishing a relation between the CD signal and the optical purity of the chiral compound;
(3) adding a chiral compound solution with unknown optical purity into the axial chiral biphenyl compound solution prepared in the step (1), reacting, detecting signals of the obtained product through a Circular Dichroism (CD), and determining the optical purity of the chiral compound solution based on the relation between the CD signals established in the step (2) and the optical purity of the chiral compound.
According to the present invention, in the step (1), the solution of the axial chiral biphenyl compound is preferably a solution prepared by dissolving the axial chiral biphenyl compound in a nitrile solvent, for example, a solution prepared by dissolving the axial chiral biphenyl compound in acetonitrile.
The concentration of the axial chiral biphenyl compound solution can be 17mmol/L to 29mmol/L, preferably 20mmol/L to 26mmol/L, such as 23 mmol/L.
According to the present invention, when the method is used for measuring the optical purity of a chiral alcohol, an acid catalyst and/or a dehydrating agent may be added to the solution of step (1);
the acidic catalyst is selected from methanesulfonic acid;
the mass ratio of the acidic catalyst to the axial chiral biphenyl compound may be (0.1-0.7) to 1, preferably (0.2-0.6) to 1, e.g. 0.375: 1;
the dehydrating agent is selected from molecular sieves.
The amount of the dehydrating solvent used in the present invention is not particularly limited, and for example, 1 to 5 molecular sieves, preferably 1 molecular sieve, can be used.
According to the present invention, when the method is used for measuring the optical purity of chiral amines, a dehydrating agent, and optionally a basic compound, may be added to the solution of step (1);
the dehydrating agent is selected from molecular sieves;
the amount of the dehydrating solvent used in the present invention is not particularly limited, and for example, 1 to 5 molecular sieves, preferably 1 molecular sieve, can be used.
The basic compound is selected from triethylamine.
The mass ratio of the basic compound to the axial chiral biphenyl compound may be (0-0.5):1, preferably (0-0.1):1, e.g. 0, 0.875: 1.
According to the invention, in step (2), the optical purity of the solution of chiral compound of known optical purity is selected, for example, from-100%, -66.67%, -33.33%, 0, 33.33%, 66.67%, 100%.
According to the invention, the axial chiral biphenyl compound reacted with the chiral compound may be a compound of formula (a) or a compound of formula (B), preferably a compound of formula (B);
the temperature of the reaction may be 0-60 ℃;
the reaction time may be 6-12 hours;
according to the invention, a linear relation graph of optical purity and CD intensity can be established by taking the CD intensity value at the position of a peak of 225nm-285nm, preferably the CD intensity value at the position of 245nm-265nm, such as the CD intensity values at the positions of 245nm, 260nm and 265 nm.
The invention has the advantages of
(1) The axial chiral biphenyl compound is designed and synthesized, and has a ring-chain tautomer, the preparation method of the invention does not need complicated separation and purification, is simple to operate, and has the advantages of easy product purification, good stability, good reproducibility and stable chemical properties of the product.
(2) The biphenyl axis chiral compound has excellent reactivity with chiral alcohol, primary amine and secondary amine with single functional group, and high conversion rate. The diastereoisomer formed after the reaction has stronger CD signal and is easy to detect. Has great application prospect in the aspect of optical purity detection of high-throughput chiral alcohol, primary amine and secondary amine.
(3) The method for determining the optical purity of the chiral alcohol, the primary amine and the secondary amine overcomes the defects of the conventional measuring methods (such as a chromatography method, a nuclear magnetic method and an optical rotation method), and has the advantages of high measuring precision, short time consumption, low cost, easiness in popularization and the like. The invention provides a brand-new measuring method for optical purity of chiral alcohol and amine with single functional group. Furthermore, the detection limit of the measurement method of the present invention is low, and the optical purity of chiral 3-methyl-2-butanol, 1-phenylethylamine and 2- (methoxymethyl) pyrrolidine can be measured with the compound of the present invention at a concentration of only 23 mM.
Definition and description of terms
Unless otherwise indicated, the definitions of radicals and terms set forth in the specification and claims of this application, including definitions thereof as examples, exemplary definitions, preferred definitions, definitions of particular compounds in the examples, and the like, may be combined with one another in any combination and permutation. The definitions of the groups and the structures of the compounds in such combinations and after the combination are within the scope of the present specification.
The term "C1-40Alkyl is understood to preferably mean a straight-chain or branched, saturated monovalent hydrocarbon radical having from 1 to 40 carbon atoms, preferably C1-10An alkyl group. "C1-10Alkyl "is understood to preferably mean a straight-chain or branched, saturated monovalent hydrocarbon radical having 1,2, 3,4, 5,6, 7, 8, 9 or 10 carbon atoms. The alkyl group is, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-ethylpropyl, 1, 2-dimethylpropyl, neopentyl, 1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3-dimethylbutyl, 2-dimethylbutyl, 1-dimethylbutyl, 2, 3-dimethylbutyl, 2-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3-dimethylbutyl, 2-dimethylbutyl, 1-dimethylbutyl, 2,1, 3-dimethylbutyl or 1, 2-dimethylbutyl, and the like, or isomers thereof. In particular, the radicals have 1,2, 3,4, 5,6 carbon atoms ("C)1-6Alkyl groups) such as methyl, ethyl, propyl, butyl, isopropyl, isobutyl, sec-butyl, tert-butyl, more particularly groups having 1,2 or 3 carbon atoms ("C)1-3Alkyl groups) such as methyl, ethyl, n-propyl or isopropyl.
The term "C2-40Alkenyl "is understood to preferably mean a straight-chain or branched monovalent hydrocarbon radical comprising one or more double bonds and having from 2 to 40 carbon atoms, preferably" C2-10Alkenyl ". "C2-10Alkenyl "is understood to preferably mean a straight-chain or branched, monovalent hydrocarbon radical which contains one or more double bonds and has 2,3, 4,5, 6, 7, 8, 9 or 10 carbon atoms, in particular 2 or 3 carbon atoms (" C2-3Alkenyl "), it being understood that in the case where the alkenyl group comprises more than one double bond, the double bonds may be separated from each other or conjugated. The alkenyl group is, for example, vinyl, allyl, (E) -2-methylvinyl, (Z) -2-methylvinyl, (E) -but-2-enyl, (Z) -but-2-enyl, (E) -but-1-enyl, (Z) -but-1-enyl, pent-4-enyl, (E) -pent-3-enyl, (Z) -pent-3-enyl, (E) -pent-2-enyl, (Z) -pent-2-enyl, (E) -pent-1-enyl, (Z) -pent-1-enyl, hex-5-enyl, (E) -hex-4-enyl, (Z) -hex-4-enyl, m-n-2-enyl, m-n-1-enyl, m-n-E-4-enyl, m-n-2-, (E) -hex-3-enyl, (Z) -hex-3-enyl, (E) -hex-2-enyl, (Z) -hex-2-enyl, (E) -hex-1-enyl, (Z) -hex-1-enyl, isopropenyl, 2-methylprop-2-enyl, 1-methylprop-2-enyl, 2-methylprop-1-enyl, (E) -1-methylprop-1-enyl, (Z) -1-methylprop-1-enyl, 3-methylbut-3-enyl, 2-methylbut-3-enyl, 1-methylbut-3-enyl, 3-methylbut-2-enyl, (E) -2-methylbut-2-enyl, (Z) -2-methylbut-2-enyl, (E) -1-methylbut-2-enyl, (Z) -1-methylbut-2-enyl, (E) -3-methylbut-1-enyl, (Z) -3-methylbut-1-enyl, (E) -2-methylbut-1-enyl, (Z) -2-methylbut-1-enyl, (E) -1-methylbut-1-enyl, (Z) -1-methylbut-1-enyl, 1-dimethylprop-2-enyl, 1-ethylprop-1-enyl, 1-propylvinyl group and 1-isopropylvinyl group.
The term "C2-40Alkynyl "is understood to mean a straight-chain or branched monovalent hydrocarbon radical comprising one or more triple bonds and having from 2 to 40 carbon atoms, preferably" C2-C10Alkynyl ". The term "C2-C10Alkynyl "is understood as preferably meaning a straight-chain or branched, monovalent hydrocarbon radical which contains one or more triple bonds and has 2,3, 4,5, 6, 7, 8, 9 or 10 carbon atoms, in particular 2 or 3 carbon atoms (" C2-C3-alkynyl "). The alkynyl group is, for example, ethynyl, prop-1-ynyl, prop-2-ynyl, but-1-ynyl, but-2-ynyl, but-3-ynyl, pent-1-ynyl, pent-2-ynyl, pent-3-ynyl, pent-4-ynyl, hex-1-ynyl, hex-2-ynyl, hex-3-ynyl, hex-4-ynyl, hex-5-ynyl, 1-methylprop-2-ynyl, 2-methylbut-3-ynyl, 1-methylbut-2-ynyl, 3-methylbut-1-ynyl, 1-ethylprop-2-ynyl, prop-2-ynyl, but-3-methylbut-1-ynyl, and so-1-ethylprop, 3-methylpent-4-ynyl, 2-methylpent-4-ynyl, 1-methylpent-4-ynyl, 2-methylpent-3-ynyl, 1-methylpent-3-ynyl, 4-methylpent-2-ynyl, 1-methylpent-2-ynyl, 4-methylpent-1-ynyl, 3-methylpent-1-ynyl, 2-ethylbut-3-ynyl, 1-ethylbut-2-ynyl, 1-propylprop-2-ynyl, 1-isopropylprop-2-ynyl, 2-dimethylbut-3-ynyl, 2-methylpent-4-ynyl, 1-methylpent-4-ynyl, 2-methylpent-1-ynyl, 3-methylpent-1-, 1, 1-dimethylbut-3-ynyl, 1-dimethylbut-2-ynyl or 3, 3-dimethylbut-1-ynyl. In particular, the alkynyl group is ethynyl, prop-1-ynyl or prop-2-ynyl.
The term "C3-20Cycloalkyl is understood to mean a saturated monovalent monocyclic or bicyclic hydrocarbon ring having 3 to 20 carbon atoms, preferably "C3-10Cycloalkyl groups ". The term "C3-10Cycloalkyl "is understood to mean a saturated monovalent monocyclic or bicyclic hydrocarbon ring having 3,4, 5,6, 7, 8, 9 or 10 carbon atoms. Said C is3-10Cycloalkyl groups may be monocyclic hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl or cyclodecyl, or bicyclic hydrocarbon groups such as decalin rings.
The term "3-20 membered heterocyclyl" means a saturated monovalent monocyclic or bicyclic hydrocarbon ring comprising 1-5 heteroatoms independently selected from N, O and S, preferably "3-10 membered heterocyclyl". The term "3-10 membered heterocyclyl" means a saturated monovalent monocyclic or bicyclic hydrocarbon ring comprising 1-5, preferably 1-3 heteroatoms selected from N, O and S. The heterocyclic group may be attached to the rest of the molecule through any of the carbon atoms or nitrogen atom (if present). In particular, the heterocyclic group may include, but is not limited to: 4-membered rings such as azetidinyl, oxetanyl; 5-membered rings such as tetrahydrofuranyl, dioxolyl, pyrrolidinyl, imidazolidinyl, pyrazolidinyl, pyrrolinyl; or a 6-membered ring such as tetrahydropyranyl, piperidinyl, morpholinyl, dithianyl, thiomorpholinyl, piperazinyl, or trithianyl; or a 7-membered ring such as diazepanyl. Optionally, the heterocyclic group may be benzo-fused. The heterocyclyl group may be bicyclic, for example but not limited to a 5,5 membered ring, such as a hexahydrocyclopenta [ c ] pyrrol-2 (1H) -yl ring, or a 5,6 membered bicyclic ring, such as a hexahydropyrrolo [1,2-a ] pyrazin-2 (1H) -yl ring. The nitrogen atom containing ring may be partially unsaturated, i.e., it may contain one or more double bonds, such as, but not limited to, 2, 5-dihydro-1H-pyrrolyl, 4H- [1,3,4] thiadiazinyl, 4, 5-dihydrooxazolyl, or 4H- [1,4] thiazinyl, or it may be benzo-fused, such as, but not limited to, dihydroisoquinolinyl. According to the invention, the heterocyclic radical is non-aromatic.
The term "C6-20Aryl "is understood to preferably mean a mono-, bi-or tricyclic hydrocarbon ring having a monovalent or partially aromatic character with 6 to 20 carbon atoms, preferably" C6-14Aryl ". The term "C6-14Aryl "is to be understood as preferably meaning a mono-, bi-or tricyclic hydrocarbon ring having a monovalent or partially aromatic character with 6, 7, 8, 9, 10, 11, 12, 13 or 14 carbon atoms (" C6-14Aryl group "), in particular a ring having 6 carbon atoms (" C6Aryl "), such as phenyl; or biphenyl, or is a ring having 9 carbon atoms ("C9Aryl), such as indanyl or indenyl, or a ring having 10 carbon atoms ("C10Aryl radicals), such as tetralinyl, dihydronaphthyl or naphthyl, or rings having 13 carbon atoms ("C13Aryl radicals "), examplesSuch as fluorenyl, or a ring having 14 carbon atoms ("C)14Aryl), such as anthracenyl.
The term "5-20 membered heteroaryl" is understood to include such monovalent monocyclic, bicyclic or tricyclic aromatic ring systems: having 5 to 20 ring atoms and comprising 1 to 5 heteroatoms independently selected from N, O and S, such as "5-14 membered heteroaryl". The term "5-14 membered heteroaryl" is understood to include such monovalent monocyclic, bicyclic or tricyclic aromatic ring systems: which has 5,6, 7, 8, 9, 10, 11, 12, 13 or 14 ring atoms, in particular 5 or 6 or 9 or 10 carbon atoms, and which comprises 1 to 5, preferably 1 to 3, heteroatoms each independently selected from N, O and S and, in addition, can be benzo-fused in each case. In particular, heteroaryl is selected from thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, triazolyl, thiadiazolyl, thia-4H-pyrazolyl and the like and their benzo derivatives, such as benzofuryl, benzothienyl, benzoxazolyl, benzisoxazolyl, benzimidazolyl, benzotriazolyl, indazolyl, indolyl, isoindolyl and the like; or pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, and the like, and benzo derivatives thereof, such as quinolyl, quinazolinyl, isoquinolyl, and the like; or azocinyl, indolizinyl, purinyl and the like and benzo derivatives thereof; or cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, naphthyridinyl, pteridinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, and the like.
Unless otherwise indicated, heterocyclyl, heteroaryl or heteroarylene include all possible isomeric forms thereof, e.g., positional isomers thereof. Thus, for some illustrative, non-limiting examples, pyridyl or pyridinylene includes pyridin-2-yl, pyridinylene-2-yl, pyridin-3-yl, pyridinylene-3-yl, pyridin-4-yl, and pyridinylene-4-yl; thienyl or thienylene includes thien-2-yl, thien-3-yl and thien-3-yl.
Detailed Description
The present invention will be described in further detail with reference to specific examples. It is to be understood that the following examples are only illustrative and explanatory of the present invention and should not be construed as limiting the scope of the present invention. All the technologies realized based on the above-mentioned contents of the present invention are covered in the protection scope of the present invention.
Instruments and reagents:1H-NMR was measured using a 400MHz Bruker Biospin amplitude type III NMR spectrometer; circular dichroism was measured using a French Bio-Logic model MOS-450 circular dichroism spectrometer (1cm quartz cuvette); chiral 3-methyl-2-butanol, 1-phenylethylamine, and 2- (methoxymethyl) pyrrolidine were purchased from Alfa Aesar for calibration, and all other reagents were commercially available analytical grade reagents.
Example 1
With R ═ CH3For example, 80-100mL of thionyl chloride was added to a 250mL round bottom flask containing o-bromobenzoic acid (6g,30mmol), and the reaction was terminated after 6 hours of reflux, after which thionyl chloride was removed to give a white solid with a pungent odor. 2.19g (10mmol) of this white solid was dissolved in 10mL of dichloromethane, and slowly added dropwise with stirring at 0 deg.CTo 40mL of dichloromethane containing 5-10mL of aqueous methylamine (40%), sodium carbonate (3.18g,30 mmol). After 2 hours of reaction, insoluble matter was filtered off, and the filter cake was thoroughly washed with 120mL of dichloromethane. The collected dichloromethane was washed 3 times with saturated aqueous sodium carbonate solution (40 mL. times.3), and the organic phase was separated and dried over anhydrous sodium sulfate. After filtration, methylene chloride was spin-dried to give 2.1 g of a white solid with a yield of 95% and a purity of 90%.
In the same way, R ═ C can be obtained2H5,C3H7,C4H9And the specific characterization data of the products are as follows:
R=CH3,1H NMR(400MHz,CDCl3)δ=7.59(1H,Ar H),7.53(1H,Ar H),7.36(1H,Ar H),7.28(1H,Ar H),6.08(br s,1H,NH),3.02(d,J=4.8Hz,3H,CH3).
R=C2H5the yield is 90 percent, and the purity is 95 percent.1H NMR(400MHz,CDCl3)δ=7.61(1H,Ar H),7.54(1H,Ar H),7.37(1H,Ar H),7.28(1H,Ar H),5.99(br s,1H,NH),3.50-3.54(m,2H,CH2),1.28(t,3H,CH3).
R=C3H7The yield is 92% and the purity is 95%.1H NMR(400MHz,CDCl3)δ=7.59(dd,J=8,1.2Hz,1H,Ar H),7.53(dd,J=7.6,1.6Hz,1H,Ar H),7.37(ddd,J=14.8,7.2,0.8Hz,1H,Ar H),7.29(ddd,J=15.2,7.6,0.8Hz,1H,Ar H),6.05(br s,1H,NH),3.41-3.45(m,2H,CH2),1.65-1.69(m,2H,CH2),1.02(t,3H,CH3).
R=C4H9The yield is 90 percent, and the purity is 95 percent.1H NMR(400MHz,CDCl3)δ=7.60(dd,J=8,0.8Hz,1H,Ar H),7.55(dd,J=7.2,0.8Hz,1H,Ar H),7.37(ddd,J=15.2,7.6,0.8Hz,1H,Ar H),7.28(ddd,J=15.2,7.6,1.2Hz,1H,Ar H),5.98(br s,1H,NH),3.47-3.53(m,2H,CH2),1.62-1.65(m,2H,CH2),1.44-1.47(m,2H,CH2),0.99(t,3H,CH3).
With R ═ CH3For example, the product obtained in step 1, 2-bromo-N-methylbenzamide (0.214g,1mmol), Pd (PPh) was added under nitrogen3)4(60mg,0.05mmol), CsF (0.456g,3mmol) was dissolved in a mixture of 15mL1, 4-dioxane and 8mL water, a solution of 2-formylphenylboronic acid (0.3g,2mmol) in 10mL 1, 4-dioxane was slowly added, the reaction was terminated at 80 ℃ for 18-24 hours, after the reaction solution was cooled to room temperature, the mixture was extracted twice with ethyl acetate (40 mL. times.2), the organic phase was collected, washed twice with saturated brine (40 mL. times.2) and dried over anhydrous sodium sulfate. White solid was obtained by flash column separation and recrystallized from acetonitrile to obtain 0.2g of white crystals with a yield of 83%. The presence of tautomeric compounds can be determined by nuclear magnetic data.
In the same way, R ═ C can be obtained2H5,C3H7,C4H9And the specific characterization data of the products are as follows:
R=CH3,1H NMR(400MHz,CDCl3)δ=7.50-7.60(m,12.48H,Ar H),5.83(d,J=5.2Hz,1H),5.80(d,0.6H,J=4Hz),5.11(d,J=5.2Hz,1H),4.25(d,J=4Hz,0.6H),3.22(s,1.8H),2.91(s,3H).
HR-MS:calcd for[M+H+]240.1025,found 240.1019.
calcd for[M+Na+]262.0844,found 262.0840.
R=C2H5the yield is 80 percent, and the purity is 97 percent.1H NMR(400MHz,CDCl3)δ=7.58-7.66(m,18.24H,Ar H),5.86(d,J=4Hz,1.28H),5.80(d,J=5.6Hz,1H),5.10(d,J=5.6Hz,1H),4.11(d,J=1.28Hz,4H),3.64(m,4.56H),1.16(t,J=7.2Hz,3.84H),1.07(t,J=7.2Hz,3H).
HR-MS:calcd for[M+Na+]276.1000,found 276.0997.
R=C3H7The yield is 85 percent, and the purity is 95 percent.1H NMR(400MHz,CDCl3)δ=7.50-7.62(m,19.76H,Ar H),5.84(d,J=4.4Hz,1.47H),5.79(d,J=5.6Hz,1H),5.15(d,J=5.6Hz,1H),4.16(d,J=4.4Hz,1.52H),3.69-3.75(m,1.47H),3.51-3.56(m,2.47H),3.38-3.42(m,1H),1.51-1.57(m,4.94H),0.84(t,J=7.2Hz,4.41H),0.77(t,J=7.2Hz,3H).
R=C4H9The yield is 90 percent, and the purity is 95 percent.1H NMR(400MHz,CDCl3)δ=7.55-7.66(m,20.21H,Ar H),5.84(d,J=4.4Hz,1.52H),5.81(d,J=6Hz,1H),5.01(d,J=6Hz,1H),4.06(d,J=4.4Hz,1.52H),3.72-3.77(m,1.52H),3.51-3.58(m,2.52H),3.42-3.47(m,1H),1.51-1.58(m,5.04H),1.21-1.28(m,5.04H),0.85-0.91(m,7.56H).
Example 2 determination of enantiomeric excess of chiral alcohol
The compound obtained in example 1 (R ═ CH) was synthesized using chiral 3-methyl-2-butanol as an example3) Dissolving 4mg in 0.7mL acetonitrile solution to prepare seven parts of solution with the concentration of 23mmol/L, adding 1.5mg of methanesulfonic acid and 1 particle molecular sieve into each part, then seven groups of 3-methyl-2-butanol enantiomer mixtures with known optical purities of-100%, -66.67%, -33.33%, 0, 33.33%, 66.67%, 100% were added, and after 10 hours of reaction with stirring at 20 ℃, 17. mu.L of each solution was taken out and dissolved in 3mL of acetonitrile, testing the CD signal, taking the CD intensity value at the position of 260nm of the wave peak, establishing a linear relation graph of optical purity and CD intensity, on the basis, five groups of 3-methyl-2-butanol samples with unknown optical purity are measured, and the results are shown in the following table 1, and the results are well matched with the linear fitting curve obtained before, which indicates that the chiral alcohol enantiomer excess measurement is very accurate.
TABLE 1 five groups of 3-methyl-2-butanol samples of unknown optical purity and absolute error table read from the linear fitting curve of FIG. 5
Example 3 determination of enantiomeric excess of chiral primary amine
The compound obtained in example 1 (R ═ CH) was exemplified by chiral 1-phenylethylamine3) Dissolving 4mg in 0.7mL acetonitrile solution to prepare seven parts of solution with the concentration of 23mmol/L, adding 3.5mg of triethylamine and 1 particle molecular sieve into each part, then adding seven groups of known optical purities of-100%, -66.67%,33.33 percent, 0, 33.33 percent, 66.67 percent and 100 percent of 1-phenylethylamine enantiomer mixture is stirred and reacted for 9 hours at 34 ℃, 17 mu L of solution is taken out each time and dissolved in 3mL of acetonitrile, CD signals are tested, CD intensity values at the positions of peaks 245nm are taken, a linear relation graph of optical purity and CD intensity is established, on the basis, five groups of 1-phenylethylamine samples with unknown optical purity are measured, and results are well matched with linear fitting curves obtained before, so that the enantiomeric excess measurement of the chiral primary amine is very accurate.
Example 4 determination of enantiomeric excess of chiral secondary amine
The compound obtained in example 1 (R ═ CH) was synthesized using chiral 2- (methoxymethyl) pyrrolidine as an example3) Dissolving 4mg in 0.7mL acetonitrile solution to prepare seven parts of solution with the concentration of 23mmol/L, adding 1 particle molecular sieve into each part, then seven groups of 2- (methoxymethyl) pyrrolidine enantiomer mixtures of known optical purities of-100%, -66.67%, -33.33%, 0, 33.33%, 66.67%, 100% were added, and after stirring the reaction at 53 ℃ for 9 hours, 17. mu.L of each solution was taken out and dissolved in 3mL of acetonitrile, testing the CD signal, taking the CD intensity value at the 265nm peak position to establish a linear relation graph of optical purity and CD intensity, on the basis, five groups of 2- (methoxymethyl) pyrrolidine samples with unknown optical purity are determined, and the results are well matched with the linear fitting curve obtained before, so that the enantiomeric excess determination of the 2- (methoxymethyl) pyrrolidine is very accurate.
The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.