A metal‐free approach for the synthesis of 5‐trifluoromethyl‐1,2,4‐triazoles from trifluoroacetimidoyl chlorides and hydrazones has been achieved under aerobic oxidative conditions. The reaction proceeds through a cascade base‐promoted intermolecular C−N bond formation and iodine‐mediated intramolecular C−N bond oxidative coupling sequence. The protocol features broad substrate scope and can be scaled
Copper-Catalyzed Conjugate Addition of Carbonyls as Carbanion Equivalent via Hydrazones
作者:Siyi Luo、Marie Peng、Pierre Querard、Chen-Chen Li、Chao-Jun Li
DOI:10.1021/acs.joc.1c01380
日期:2021.9.17
catalyzed by readily available copper complexes at room temperature. The employment of mesitylcopper(I) and electron-rich phosphine bidentateligand is a key factor affecting reactivity. The reaction allows various aromatic hydrazones to react with diverse conjugated compounds to produce 1,4-adducts in yields of about 20 to 99%.
hydroalkylation of dienes with stabilized carbon nucleophiles has been made, hydroalkylation of dienes with unstabilized carbon nucleophiles has remained a challenge. In this article, we report a protocol for nickel-catalyzed hydroalkylation of dienes with hydrazones, which serve as equivalents of alkyl carbon nucleophiles. In addition, we developed a protocol for hydroalkenylation of dienes with α,β-unsaturated
acyl-based carbanion equivalents. We herein report an alternative strategy that is based on the use of aldehydes as alkyl carbanion equivalents in a reductive coupling with aryl imines. A wide array of secondary amines can be synthesized in moderate to high yields. This reaction is mediated by hydrazine and catalyzed by ruthenium(II) complexes, and it tolerates various functional groups, such as esters, amides