Thermally induced reaction of diazoamides with isatins: A complementary approach to the 3,3′-bioxindole derivatives

A Pd-catalyzed one-pot cascade consisting of C-C/C-O/N-N bond formation to access benzoxazine fused 1,2,3-triazoles

A Pd-catalyzed one-pot cascade consisting of C-C/C-O/N-N bond formation to access clinically important fused 1,2,3-triazoles using N-aryl-α-(tosylhydrazone)acetamides with isocyanide has been developed. Besides, various substitutions on the N-aryl part of acetamides along with different isocyanides show good compatibility in this protocol. Next, two plausible mechanistic routes were proposed; however, one of the routes was more favourable which involved the formation of a benzoxazine ring first followed by the realization of a triazole ring. Additionally, the more favourable mechanistic route was investigated using DFT studies which suggests that the formations of a Pd(II)-isocyanide complex and α-diazoimino intermediates were key steps in the catalytic cycle.

Desaturation via Redox-Neutral Hydrogen Transfer Process: Synthesis of 2-Allyl Anilines, Mechanism and Applications

An unprecedented desaturation method via redox-neutral hydrogen transfer process has been disclosed under mild conditions for the selective formation of terminal alkene with alkyl diazo compounds and aza-o-QMs. The control experiments and DFT calculations suggest that the visible light was introduced as a key parameter to enhance the reactivity via a radical process in the formation of closed-shell cyclopropane intermediate, followed by a ring opening and redox-neutral hydrogen transfer process to give the desaturated product. The high regioselectivity in this transformation is enabled by the internal amino species as an ancillary group (AG) in the final olefin formation step. This method provides a missing link in the expeditious preparation of synthetically useful 2-allyl anilines with broad substrate generality. Further applications of these generated products in N-heterocycle construction, including 5- and 6-membered rings with structural diversity, have been tactfully explored, which highlight the potential in methodology development and drug discovery.

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Highly site and regioselective synthesis enabled by ancillary group

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Desaturation via redox-neutral inert hydrogen transfer process

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Missing link in the synthesis of 2-allyl anilines with board substrate scope

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Methodology development and diversity synthesis based on 2-allyl anilines

Synthesis of spiro-4H-pyrazole-oxindoles and fused 1H-pyrazoles via divergent, thermally induced tandem cyclization/migration of alkyne-tethered diazo compounds

A thermally induced, substrate-dependent reaction of alkynyl diazo compounds has been developed. This transformation produces spiro-4H-pyrazole-oxindoles and fused 1H-pyrazoles in good to high yields from the corresponding alpha-cyano and alpha-sulfonyl diazo compounds. The salient features of this reaction include excellent chemoselectivity and atom-economy, mild reaction conditions, simple purification and potential for large scale production.

Copper-catalyzed [4+1]-annulation of 2-alkenylindoles with diazoacetates: a facile access to dihydrocyclopenta[b]indoles

A copper-catalyzed [4+1]-annulation of 2-vinylindoles with diazoacetates: a facile access to the dihydrocyclopenta[b]indoles bearing two contiguous all-carbon quaternary centers.

Thermally induced N–S bond insertion reaction of diazo compounds with N-sulfenylsuccinimides: synthesis of sulfides and mechanism studies

A metal-free gem-functionalization reaction of diazo compounds via a formal N–S bond insertion process under mild conditions is presented.