When Ethyl Isocyanoacetate Meets Isatins: A 1,3-Dipolar/Inverse 1,3-Dipolar/Olefination Reaction for Access to 3-Ylideneoxindoles

Abstract

A new CuI/1,10-phen-catalyzed reaction for the synthesis of 3-ylideneoxindoles from readily available isatins and ethyl isocyanoacetate, in which ethyl isocyanoacetate acts as a latent two-carbon donor like the Wittig reagent, is reported. A tandem procedure including 1,3-dipolar cycloaddition/inverse 1,3-dipolar ring opening/olefination allows the preparation of 3-ylideneoxindoles with broad functional group tolerance.

A quick and regioselective access of spirooxindole‐oxazoline by reaction of isatin and isocyanoacetate “on water”

“…The DEPT‐135 experiment confirmed the presence of one ─CH 2 at δ 61.37 ppm. The spectral data of 3a were found in full agreement with the reported data …”

Organocatalytic Decarboxylative Cyanomethylation of Difluoromethyl and Trifluoromethyl Ketones

“…Substantial progress has been made with regard to the cyanomethylation of aldehydes and imines by the introduction of Me 3 SiCH 2 CN or other α‐cyano carbanion precursors and through the development of mild transition metal catalyzed procedures that address the challenging low acidity of acetonitrile (pKa 31.3 in DMSO) . In addition, decarboxylative cyanomethylation and superbase catalyzed acetonitrile additions have emerged as a practical alternative ,…”

“…[2] In addition, decarboxylative cyanomethylation and superbase catalyzed acetonitrile additions have emerged as a practical alternative. [3,4] …”

Advances in the Synthesis of Benzo‐Fused Spiro Nitrogen Heterocycles: New Approaches and Modification of Old Strategies

“…The first reaction product is thermally unstable and upon heating in toluene, the spiroheterocyclic compound 24 smoothly transforms into 2-indolone 25 (Scheme 8). [114] Noteworthy is the new enantioselective threecomponent spirocyclization, which takes place as a sequence of domino Knoevenagel/Michael/cyclization reactions in the presence of a binuclear zinc catalyst. A wide range of chiral 3,3-dihydrofuran spirooxindoles 26 was synthesized from isatins 22 upon interaction with malononitrile and hydroxymethyl phenyl ketone 27 (1 : 1 : 1 ratio) in the presence of 2-10 mol-% 2diarylmethyl substituted 2,6-bis(azetidin-1-ylmethyl)-(n = 0) or 2,6-bis(pyrrolidin-1-ylmethyl)phenols (n = 1) as ligand, 4 Å MS and 2 -20 mol-% ZnEt 2 in dichloromethane under mild conditions.…”