Regioselective Carbon-Carbon Bond Formation in Titanium Mediated Reaction of Ethylmagnesium Bromide with Allylic Alcohols and Allylic Ethers
作者:Oleg G. Kulinkovich、Oleg L. Epstein、Vladimir E. Isakov、Ekaterina A. Khmel'nitskaya
DOI:10.1055/s-2001-9707
日期:——
In the presence of Ti(Oi-Pr)4 reaction of EtMgBr with allylic alcohols and allylicethers affords the products of formal SN2′ substitution of hydroxy or alkoxy groups with ethyl groups in moderate to good yields and excellent regioselectivity. The mechanism of the reaction includes the formation of titanacyclopropanes as the key organometallic intermediates. Promoting action of EtMgBr on the process
Bidentate NHC-Based Chiral Ligands for Efficient Cu-Catalyzed Enantioselective Allylic Alkylations: Structure and Activity of an Air-Stable Chiral Cu Complex
作者:Andrew O. Larsen、Wenhao Leu、Christina Nieto Oberhuber、John E. Campbell、Amir H. Hoveyda
DOI:10.1021/ja046245j
日期:2004.9.1
Cu-catalyzed addition of alkylzincreagents to a range of allylic phosphates is promoted efficiently and with high enantioselectivity to afford tertiary as well as quaternarycarbon centers (up to 98% ee). Reactions proceed to completion with 0.5-5 mol % catalyst loading and are best promoted by commercially available CuCl2.2H2O. The X-ray structure of the chiral NHC-Ag(I) complex used in the study
Cu催化的烷基锌试剂向一系列烯丙基磷酸酯的加成得到有效促进,并具有高对映选择性,以提供叔和季碳中心(高达 98% ee)。反应在 0.5-5 mol% 的催化剂负载下进行到完成,最好由市售的 CuCl2.2H2O 促进。还报告了研究中使用的手性 NHC-Ag(I) 配合物以及具有催化活性的 NHC-Cu(II) 配合物的 X 射线结构;两种复合物都是空气稳定的,并且以 >/=95% 的分离产率形成。可在空气中处理的分离出的 Cu 络合物具有催化活性。本报告为使用手性 NHC 配体进行有效的铜催化烯丙基烷基化提供了第一个先例。
A convenient coupling reaction of allyl alcohols with grignard reagents using 1-chloro-2-methyl-N,N-tetramethylenepropenylamine
作者:Tamotsu Fujisawa、Sachio Iida、Hisashi Yukizaki、Toshio Sato
DOI:10.1016/s0040-4039(00)94190-x
日期:1983.1
1-Chloro-2-methyl-N,N-tetramethylenepropenylamine was found to be a good condensation reagent for a regioselective coupling reaction of allyl alcohols with Grignard reagents under mild conditions to afford olefinic products.