Copper/iron controlled regioselective 1,2-carboazidation of 1,3-dienes with acetonitrile and azidotrimethylsilane

Carboazidation and diazidation were carried out on 1,3-diene compounds using TMSN3 as the azide source and MeCN as the cyanoalkylation reagent. This method exhibits excellent functional group tolerance, a broad substrate range, and a short reaction time, providing an effective pathway for synthesizing valuable azides. Our report introduces an unprecedented strategy for the carboazidation and diazidation of 1,3-dienes, with mechanism studies indicating that the reaction involves a radical pathway.

Chemoselective Cu-catalyzed synthesis of diverse N-arylindole carboxamides, β-oxo amides and N-arylindole-3-carbonitriles using diaryliodonium salts

Chemoselective copper-catalyzed synthesis of diverse N-arylindole-3-carboxamides, β-oxo amides and N-arylindole-3-carbonitriles from readily accessible indole-3-carbonitriles, α-cyano ketones and diaryliodonium salts has been developed. Diverse N-arylindole-3-carboxamides and β-oxo amides were successfully achieved in high yields under copper-catalyzed neutral reaction conditions, and the addition of an organic base (DIPEA) resulted in a completely different selectivity pattern to produce N-arylindole-3-carbonitriles. Moreover, the importance of the developed methodology was realized by the synthesis of indoloquinolones and N-((1H-indol-3-yl)methyl)aniline and by a single-step gram-scale synthesis of the naturally occurring cephalandole A analogue.

Transition metal-catalyzed synthesis of spirooxindoles

Spirooxindole is a principal bioactive agent and is observed in several natural products including alkaloids. They are broadly studied in the pharmaceutical field and have a significant role in the evolution of drugs such as anti-viral, anti-cancer, anti-microbial etc. In organic chemistry, an indispensable role is presented by transition metal catalysts. An effective synthetic perspective to spirooxindoles is the use of transition metals as the catalyst. This review discusses the synthesis of spirooxindoles catalyzed by transition metals and covers literature up to 2020.

Copper-promoted cyanoalkylation/ring-expansion of vinylcyclopropanes with α-C-H bonds in alkylnitriles toward 3,4-dihydronaphthalenes

A copper-promoted oxidative cyanomethylation/ring-expansion of vinylcyclopropanes with α-C(sp3)-H bonds in alkyl nitriles is established for the generation of 1-cyanoethylated 3,4-dihydronaphthalenes. This cyanomethylation/ring-expansion involves a radical pathway and proceeds via cyanomethyl radical formation, radical addition and ring-expansion. This ring-expansion strategy offers a highly atom-economical route for the construction of nitrile-containing 3,4-dihydronaphthalenes, which can be transformed into other useful products under simple conditions.

Application of isatin-derived saturated esters in the synthesis of 3,3'-spirooxindole γ-butyrolactams

Stable while reactive isatin-derived saturated esters have been utilized as 3-carbon synthons in a base-promoted formal [3 + 2] annulation with N-Boc imines. The developed protocol offers a direct pathway for the rapid and divergent construction of two classes of 3,3'-spirooxindole γ-butyrolactam skeletons that are recognized as the privileged structures of various bioactive compounds. This protocol also has the advantages of mild reaction conditions, scalability and wide reaction scope.

Oxidative 1,2-carboamination of alkenes with alkyl nitriles and amines toward γ-amino alkyl nitriles

Difunctionalization of alkenes has become a powerful tool for quickly increasing molecular complexity in synthesis. Despite significant progress in the area of alkene difunctionalization involving the incorporation of a nitrogen atom across the C-C double bonds, approaches for the direct 1,2-carboamination of alkenes to produce linear N-containing molecules are scarce and remain a formidable challenge. Here we describe a radical-mediated oxidative intermolecular 1,2-alkylamination of alkenes with alkyl nitriles and amines involving C(sp³)-H oxidative functionalization catalysed by a combination of Ag₂CO₃ with iron Lewis acids. This three-component alkene 1,2-alkylamination method is initiated by the C(sp³)-H oxidative radical functionalization, which enables one-step formation of two new chemical bonds, a C-C bond and a C-N bond, to selectively produce γ-amino alkyl nitriles.

A novel coupling reaction of α-halo ketones promoted by SmI3/CuI

In the presence of SmI₃ and catalyzed by CuI in DMF, α-haloketones were transformed unexpectedly into α-hydroxy-1,4-diketones. The mechanism was probed and DMF was assumed to play a dual role both as a hydroxyl source and as a solvent.