Rhodium(III)-Catalyzed<i>ortho</i>Alkenylation of<i>N</i>-Phenoxyacetamides with<i>N</i>-Tosylhydrazones or Diazoesters through CH Activation
作者:Fangdong Hu、Ying Xia、Fei Ye、Zhenxing Liu、Chen Ma、Yan Zhang、Jianbo Wang
DOI:10.1002/anie.201309650
日期:2014.1.27
A coupling reaction of N‐phenoxyacetamides with N‐tosylhydrazones or diazoestersthrough RhIII‐catalyzed CHactivation is reported. In this reaction, ortho‐alkenyl phenols were obtained in good yields and with excellent regio‐ and stereoselectivity. Rh–carbene migratory insertion is proposed as the key step in the reaction mechanism.
Reaction of Diazo Compounds with Difluorocarbene: An Efficient Approach towards 1,1-Difluoroolefins
作者:Zhikun Zhang、Weizhi Yu、Chenggui Wu、Chengpeng Wang、Yan Zhang、Jianbo Wang
DOI:10.1002/anie.201509711
日期:2016.1.4
e difluoromethylenation of diazocompounds that proceeds under mild conditions has been developed and is based on the use of TMSCF2Br as the difluoromethylene source and tetrabutylammonium bromide (TBAB) as the promoter. The chemoselective formal carbene dimerization reaction is achieved owing to the electronic properties and the relative stability of the difluorocarbene intermediate.
Copper(I)-Catalyzed Chemoselective Coupling of Cyclopropanols with Diazoesters: Ring-Opening C−C Bond Formations
作者:Hang Zhang、Guojiao Wu、Heng Yi、Tong Sun、Bo Wang、Yan Zhang、Guangbin Dong、Jianbo Wang
DOI:10.1002/anie.201612138
日期:2017.3.27
Reported herein is an exceptional chemoselective ring‐opening/C(sp3)−C(sp3) bond formation in the copper(I)‐catalyzed reaction of cyclopropanols with diazo esters. The conventional O−H insertion product is essentially suppressed by judicious choice of reaction conditions. DFT calculations provide insights into the reaction mechanism and the rationale for this unusual chemoselectivity.
We present a new [3+2] cycloaddition reaction between alkyl–acceptor diazoalkanes under visible light irradiation. By employing easily accessible alkyl–acceptor-type diazoalkanes or their precursor hydrazones as both 1,3-dipoles and dipolarophiles, a diverse range of pyrazoline derivatives featuring a quaternary center have been efficiently synthesized in a predictable manner, with excellent functional