Bharat Kumar Allam

A Direct Metal-Free Decarboxylative Sulfono Functionalization (DSF) of Cinnamic Acids to α,β-Unsaturated Phenyl Sulfones

A metal-free room temperature decarboxylative cross-coupling between cinnamic acids and arylsulfonyl hydrazides has been realized for the first time for the synthesis of (E)-vinyl sulfones. The scope and versatility of the reaction has been demonstrated by the regio- and stereoselective synthesis of 22 derivatives with diverse structural features.

Hypervalent iodine catalyzed transamidation of carboxamides with amines

This protocol describes the catalytic use of diacetoxyiodobenzene (DIB) for the efficient transamidation of carboxamides with amines under mild conditions.

A binuclear Mn(II) complex as an efficient catalyst for transamidation of carboxamides with amines

A binuclear Mn(II) complex has been synthesized and characterized by different structural methods. The complex contains two unique oxo-bridged metal centres and has been explored as an excellent catalyst for transamidation of carboxamides with amines under solvent-free conditions.

A simple and sustainable tetrabutylammonium fluoride (TBAF)-catalyzed synthesis of azaarene-substituted 3-hydroxy-2-oxindoles through sp3 C–H functionalization

A green, practical, and metal-free protocol for direct addition of α-and γ-alkylazaarenes to isatins has been developed via sp3 C–H functionalization in water under controlled microwave radiation. This methodology provides a mild and fast route to biologically important azaarene-substituted 3-hydroxy-2-oxindoles in good to excellent yields.

Utilization of carbon disulfide as a powerful building block for the synthesis of 2-aminobenzoxazoles

This protocol describes a novel, mild and convenient route to afford 2-aminobenzoxazoles in high yields, and represents a significant advance towards an environmentally friendly strategy. Aliphatic amines are made to react with carbon disulfide to provide intermediate dithiocarbamates (DTC), which in the presence of 2-aminophenol, subsequently undergo successive intermolecular nucleophilic attack and desulfurization to produce 2-aminobenzoxazoles within 3 h.

A binuclear Cu(I) complex as a novel catalyst towards the direct synthesis of N-2-aryl-substituted-1,2,3-triazoles from chalcones

A binuclear Cu(I) complex containing a N′,N′-bis{(1H-indol-3-yl)methylene}oxalohydrazide (H2bioh) ligand has been synthesized and characterized. The molecular structures of the synthesized compounds have been determined by single crystal X-ray diffraction. The crystal structures are stabilized by inter- and intra-molecular π–π stacking and C–H⋯π interactions. The Cu(I)-complex has successfully been employed as an efficient catalyst for one-pot operation involving the azide–chalcone click reaction and subsequent arylation has been developed. The complex exhibits excellent catalytic activity with significantly low catalyst loading. The overall process is insensitive to air and moisture and can be manipulated under ambient temperature with operational ease.