Substitution reactions of secondary halides and epoxides with higher order, mixed organocuprates, R2Cu(CN)Li2: synthetic, stereochemical, and mechanistic aspects
Reactions of stoichiometric higher order, mixed lithio magnesio organocuprates
作者:Bruce H. Lipshutz、David A. Parker、Sam L. Nguyen、Keith E. McCarthy、John C. Barton、Scott E. Whitney、Hiyoshizo Kotsuki
DOI:10.1016/s0040-4020(01)90576-9
日期:1986.1
2-lithiothiophene and RMgX. Reactions of various members of this new class of reagents are described, including substitution and conjugateaddition processes, where the ligand derived from the Grignard reagent is selectively transferred. The effects of added BF3.Et2O are discussed. Some comparison reactions with the corresponding lower order reagents, RCu(CN)MgBr, have also been carried out. Evidence is presented
Cu-Catalyzed Cascades to Carbocycles: Union of Diaryliodonium Salts with Alkenes or Alkynes Exploiting Remote Carbocations
作者:Fengzhi Zhang、Shoubhik Das、Andrew J. Walkinshaw、Alicia Casitas、Michael Taylor、Marcos G. Suero、Matthew J. Gaunt
DOI:10.1021/ja504361y
日期:2014.6.25
Copper-catalyzed cascade reactions between alkenes or alkynes and diaryliodonium salts form carbocyclic products in a single step. Arylation of the unsaturated functional group is proposed to form a carbocation intermediate that facilitates hydride shift pathways to translocate the positive charge to a remote position and enables ring formation via a Friedel-Crafts-type reaction.
Treatment of alkyl halides, including tertiary alkyl bromides, with benzylic or allylic Grignard reagent in the presence of a catalytic amount of silver nitrate in ether yielded the corresponding cross-coupling products in high yields. The coupling reactions of tertiary alkyl halides provide efficient access to quaternary carbon centers.
Utilization of Tetrabutylammonium Triphenyldifluorosilicate as a Fluoride Source for Silicon−Carbon Bond Cleavage
作者:Anthony S. Pilcher、Philip DeShong
DOI:10.1021/jo960922d
日期:1996.1.1
Tetrabutylammonium triphenyldifluorosilicate (TBAT) can be employed as a fluoride source to cleave silicon-carbon bonds thus generating in situ carbanions that coupled with a variety of electrophiles, including aldehydes and ketones, in moderate to high yields. Among the examples reported is the first instance of fluoride-induced intermolecular coupling between allyltrimethylsilane and imine derivatives
Copper-Catalyzed Allylation of Alkyl Halides with Allylic Grignard Reagents
作者:Masahiro Sai、Hideki Yorimitsu、Koichiro Oshima
DOI:10.1246/bcsj.82.1194
日期:2009.9.15
Treatment of alkyl halides, including secondary and tertiary alkyl bromides, with allylic Grignardreagents in the presence of a catalytic amount of copper(II) triflate in diisopropyl ether at 25°C yielded the corresponding allylated products in high yields. The coupling reactions of tertiary alkyl halides lead to construction of allylated quaternary carbon centers. The active species is likely to
在催化量的三氟甲磺酸铜 (II) 存在于二异丙醚中的情况下,在 25°C 下用烯丙基格氏试剂处理烷基卤化物,包括仲和叔烷基溴,以高产率得到相应的烯丙基化产物。叔烷基卤化物的偶联反应导致烯丙基化季碳中心的构建。活性物质可能是烯丙基铜酸盐。