Rhodium-catalyzed coupling-cyclization reaction of isocyanides and 2-azidophenyloxyacrylates: synthesis of N-(3-substituted benzo[d]oxazol-2(3H)-ylidene)amines and dihydrobenzo[d]oxazoles

Abstract

A rhodium-catalyzed coupling cyclization of isocyanides with 2-azidophenyloxyacrylates has been developed for the first time. This reaction allows divergent syntheses of two significant N-heterocycles, five-membered N-(3-substituted benzo[d]oxazol-2(3H)-ylidene)amines and dihydrobenzo[d]oxazoles, from...

Rhodium-catalyzed coupling-cyclization ofo-alkynyl/propargyl arylazides oro-azidoaryl acetylenic ketones with arylisocyanides: synthesis of 6H-indolo[2,3-b]quinolines, dibenzonaphthyridones and dihydrodibenzo[b,g] [1,8]-naphthyridines

“…In 2016, Zhang and co-workers reported an efficient rhodium-catalyzed coupling cyclization of o-alkynyl arylazides with two σ-donor/π-acceptor ligands (isonitriles and CO) to give pyrrolo [2,3-b]indole scaffolds (Scheme 1(a)). 14 As a continuation of our studies on the applications of isocyanides 15 and alkynes, 16 herein we report a rhodium-catalyzed coupling-cyclization of o-alkynyl/propargyl arylazides or o-azidoaryl acetylenic ketones with arylisocyanides. In this reaction, the highly reactive arylcarbodiimide intermediates generated via the coupling of o-alkynyl/propargyl Initially, the model reaction of 1-azido-2-(phenylethynyl) benzene 1a with arylisocyanide 2a was examined to optimize the reaction conditions and the results are summarized in Table 1.…”

Palladium/copper-cocatalyzed three-component tandem cyclization of o-alkenyl arylisocyanides and sulfur ylides with alcohols: direct synthesis of spiro 3,3′-cyclopropyl oxindoles

“…15 Despite these research efforts, exploiting novel cyclization reactions of o-alkenyl arylisocyanides for the construction of other valuable fused azaheterocycles is still in need. As part of our continuing interest in the applications of isocyanides, 16 herein we report a novel palladium/copper-cocatalyzed three-component cascade cyclization of o-alkenyl arylisocyanides and sulfur ylides with alcohols. The reaction provides a simple and efficient strategy for the direct synthesis of spiro 3,3′-cyclopropyl oxindoles from easily available acyclic starting materials in a single step.…”

DTBP‐promoted Passerini‐type reaction of isocyanides with aldehydes: Synthesis of α‐acyloxycarboxamides

“…[ 17 ] However, these reactions are limited to aliphatic isocyanides (Scheme 1, (1)). With our continued interest in the synthetic applications of isocyanides [ 18 ] and multicomponent reactions, [ 19 ] herein we report a DTBP‐promoted Passerini‐type reaction of isocyanides with two molecular aldehydes. The reaction demonstrates the wide scope of various isocyanides, especially aromatic isocyanides, and provides an efficient strategy for the synthesis of α‐acyloxycarboxamides with two identical functional groups in a single step (Scheme 1, (2)).…”