Cu-catalyzed Fe-driven C(sp)-C(sp) and C(s)p-C(sp2) cross-coupling: an access to 1,3-diynes and 1,3-enynes.

An efficient Csp-Csp cross-coupling of alkynyl bromide and pinacol ester of alkynyl boronic acid catalyzed by CuFe2O4 nanoparticles has been accomplished in dimethyl carbonate to produce unsymmetric 1,3-diynes. This protocol is also extended for the Csp-Csp2 coupling of alkynyl bromide and alkenyl boronic acid to provide conjugated 1,3-enynes. The aliphatic, aromatic, and heteroaromatic alkynes couple with various substituted alkynyl/alkenyl boronates/boronic acids by this procedure to furnish a library of 1,3-diynes and enynes in high yields.

tert-Butyl nitrite mediated regiospecific nitration of (E)-azoarenes through palladium-catalyzed directed C-H activation.

An efficient protocol for the Pd-catalyzed regiospecific ortho-nitration of (E)-azoarenes has been achieved for the first time using tBuONO as a nitrating agent under atmospheric oxygen. A series of both symmetrical and unsymmetrical azoarenes were nitrated efficiently by this procedure providing excellent chemo- and regioselectivity and compatibility with a broad array of functional groups.

Visible light photocatalyzed direct conversion of aryl-/heteroarylamines to selenides at room temperature.

A novel strategy for the direct conversion of aryl- and heteroarylamines to selenides has been developed via diazotization of amines with tert-butyl nitrite in neutral medium followed by reaction with diaryl/diheteroaryl/dialkyl diselenides in one pot under photocatalysis at room temperature in the absence of any metal. This reaction is also applied for the synthesis of tellurides. The selenylation of heteroarylamine by this protocol is of much significance because of the difficulty in diazotization of these molecules by a standard diazotization method in acid medium.

Highly selective reduction of nitroarenes by iron(0) nanoparticles in water.

Highly selective reduction of nitroarenes has been achieved using iron metal nanoparticles in water at room temperature. A wide spectrum of reducible functionalities remained inert under the reaction conditions. During the reaction a change in shape of Fe nanoparticles was observed.

Copper nanoparticle-catalyzed carbon-carbon and carbon-heteroatom bond formation with a greener perspective.

The carbon-carbon and carbon-heteroatom bond formations constitute the backbone of organic synthesis and have been widely used in the synthesis of natural products and useful compounds. Because of growing environmental concern, more attention has been focussed on the development of greener methods. Copper is environment-friendly and comparatively inexpensive.

Hydrogenation of azides over copper nanoparticle surface using ammonium formate in water.

Aryl azides undergo clean reduction by copper nanoparticles and ammonium formate in water. The surface hydrogen on copper nanoparticles is considered to be the active reducing species. A variety of functionalized aryl azides and aryl sulfonyl azides are reduced by this procedure to the corresponding amines with excellent chemoselectivity in high yields.