Balaji V Rokade

A mild and convenient method for the synthesis of amides
has been explored by using secondary alcohols, Cu(ClO4)
2·6H2O as a catalyst, and trimethylsilyl azide (TMSN3) as a
nitrogen source in the presence of 2,3-dichloro-5,6-dicyanop-
benzoquinone (DDQ) at ambient temperature. This
method has been successfully adapted to the preparation of azides directly from their corresponding alcohols and offers
excellent chemoselectivity in the formation of ω-halo azides
and the azidation of allylic alcohols in the presence of a
benzyl alcohol moiety. In addition, this strategy provides an
opportunity to synthesize azides that can serve as precursors
to β-amino acids.

A novel, mild and convenient method for the nitrodecarboxylation
of substituted cinnamic acid derivatives to their nitroolefins
is achieved using a catalytic amount of CuCl (10 mol%) and tertbutyl
nitrite (2 equiv.) as a nitrating agent in the presence of air.
This reaction provides a useful method for the synthesis of β,β-disubstituted
nitroolefin derivatives, which are generally difficult to
access from other conventional methods. Additionally, this reaction
is selective as the E-isomer of the acid derivatives furnishes
the corresponding E-nitroolefins. One more salient feature of the
method is, unlike other methods, no metal nitrates or HNO3 are
employed for the transformation.

Copper-catalyzed, ligand-promoted decarboxylative
coupling of readily available α,β-unsaturated acids with sodium aryl
sulfinates is presented. This method provides a new avenue for the
synthesis of vinyl sulfones via a decarboxylative radical coupling
strategy by employing a catalytic amount of Cu(ClO4)2·6H2O,
TBHP in decane as an oxidant, and 1,10-phenanthroline as a ligand. The salient feature of this method is that it furnishes
exclusively the (E)-isomer.

A mild and convenient oxidative transformation
of secondary alcohols to 1,5-disubstituted
tetrazoles is uncovered by employing trimethylsilyl
azide (TMSN3) as a nitrogen source in the presence
of a catalytic amount of copper(II) perchlorate
hexaACHTUNGTRENUNGhydrate [CuACHTUNGTRENUNG(ClO4)2
.6H2O] (5 mol%) and 2,3-
dichloro-5,6-dicyano-para-benzoquinone (DDQ)
(1.2 equiv.) as an oxidant. This reaction is performed
under ambient conditions and proceeds
through CC bond cleavage.

An excellent utility of Schmidt reaction of aldehydes to access
corresponding nitriles in an instantaneous reaction is demonstrated. The
reaction of aldehydes with NaN3 and TfOH furnishes the corresponding
nitriles in near quantitative yields and tolerates a variety of electronwithdrawing
and electron-donating substituents on the substrates. Formanilides,
a common side product in Schmidt reaction, is not observed in this
reaction. Besides these advantages, the salient feature of this reaction is that it
exhibits a remarkable chemoselectivity, as acid and ketone functionalities are
well tolerated under the reaction conditions. The reaction is easily scalable,
high yielding, and nearly instantaneous.

An efficient methodology to oxidize benzylic and cinnamyl
alcohols to their corresponding nitriles in excellent yields has been developed. This methodology employs DDQ as an oxidant and TMSN3 as a source of nitrogen in the presence of a catalytic amount of Cu(ClO4)26H2O.

Copper-catalyzed, ligand-promoted decarboxylative coupling of readily available α,β-unsaturated acids with sodium aryl sulfinates is presented. This method provides a new avenue for the synthesis of vinyl sulfones via a decarboxylative radical coupling strategy by employing a catalytic amount of Cu(ClO4)2·6H2O, TBHP in decane as an oxidant, and 1,10-phenanthroline as a ligand. The salient feature of this method is that it furnishes exclusively the (E)-isomer.