Ultrafine Copper Oxide Particles Dispersed on Nitrogen-Doped Hollow Carbon Nanospheres for Oxidative Esterification of Biomass-Derived 5-Hydroxymethylfurfural.

One-pot synthesis of furan-2,5-dimethylcarboxylate (FDMC) from 5-hydroxymethylfurfural (HMF) is highly demanding for the commercial production of polyethylene furanoate (PEF). Herein, a direct synthesis of FDMC is reported from oxidative esterification of HMF using ultrafine CuO particles dispersed on nitrogen-doped hollow carbon nanospheres (CuO/N-C-HNSs) as a catalyst and tert-butyl hydroperoxide (TBHP) as an oxidizing and methylating reagent. The CuO/N-C-HNSs was prepared through a template protection-sacrifice strategy using SiO as a sacrificial template and histidine as the precursor for N and C.

Copper Catalyzed C-H Activation.

Activation of C-H bonds and their application in cross coupling chemistry has received a wider interest in recent years. The conventional strategy in cross coupling reaction involves the pre-functionalization step of coupling reactants such as organic halides, pseudo-halides and organometallic reagents. The C-H activation facilitates a simple and straight forward approach devoid of pre-functionalization step.

Metal free oxidative coupling of aryl formamides with alcohols for the synthesis of carbamates.

A direct transformation of N-aryl formamides to the corresponding carbamates via the formation of isocyanate intermediates is achieved in good yields using hypervalent iodine as an oxidant.

Copper catalyzed oxidative coupling of amines with formamides: a new approach for the synthesis of unsymmetrical urea derivatives.

Direct access to unsymmetrical urea derivatives via copper catalysed C-H/N-H coupling of formamides with amines has been developed at room temperature. This protocol is also applied to the synthesis of chiral urea derivatives.

Simple metal-free organic D-pi-A dyes with alkoxy- or fluorine substitutions: application in dye sensitized solar cells.

Two new metal-free organic sensitizers with simplest structural variations have been synthesized for application in nanocrystalline TiO2 sensitized solar cells. The donor-pi-bridge-acceptor (D-pi-A) structure dyes, Y2 and Y3 each designed with three parts, an electron donor unit (substituted phenyl), a linker unit (thiophene), and an anchor unit (cyanoacrylic acid) showed maximal monochromatic incident photon to current conversion efficiencies (IPCE) in a device reaching upto 67% and 82% respectively. The organic sensitizers with 3,4,5-trimethoxy phenyl (Y3) as donor moieties obtained better solar light to electrical energy conversion efficiencies of 3.