Coordination-Induced Stereocontrol over Carbocations: Asymmetric Reductive Deoxygenation of Racemic Tertiary Alcohols
作者:Mayuko Isomura、David A. Petrone、Erick M. Carreira
DOI:10.1021/jacs.9b00862
日期:2019.3.20
intermediate tertiary carbocations. This approach has been implemented to achieve the first example of enantioselective reductive deoxygenation of tertiaryalcohols. This reduction occurs with high enantio- (up to 96% ee) and regioselectivity (up to >50:1 rr) by applying a novel Hantzsch ester analogue as a convenient hydride source. In-depth mechanistic studies support the involvement of a tertiary carbocation
Synthesis of Vinyl-, Allyl-, and 2-Boryl Allylboronates via a Highly Selective Copper-Catalyzed Borylation of Propargylic Alcohols
作者:Lujia Mao、Rüdiger Bertermann、Katharina Emmert、Kálmán J. Szabó、Todd B. Marder
DOI:10.1021/acs.orglett.7b03294
日期:2017.12.15
An efficient methodology for the synthesis of vinyl-, allyl-, and (E)-2-boryl allylboronates from propargylic alcohols via Cu-catalyzed borylation under mild conditions is reported. In the presence of commercially available Cu(OAc)2 or Cu(acac)2 and Xantphos, the reaction affords the desired products in up to 92% yield with a broad substrate scope (43 examples). Isolation of an allenyl boronate as
Selective reduction of alkynes to cis-alkenes by hydrometallation using [(Ph3P)CuH]6.
作者:John F. Daeuble、Colleen McGettigan、Jeffrey M. Stryker
DOI:10.1016/s0040-4039(00)97371-4
日期:1990.1
Selective reduction of alkynes to the corresponding alkenes is reported using the stable, readily prepared copper(I) hydride reagent, [(Ph3P)CuH]6. Terminal alkynes are reduced at room temperature, unactivated internal alkynes react only at elevated temperature. Disubstituted alkynes with propargyl activation are also reduced, giving cis-olefins selectively. Protection of propargylic alcohol functionality
The site‐selective allylative and allenylative dearomatization of indoles with alcohols was performed under carbocatalytic regime in the presence of grapheneoxide (GO, 10 wt % loading) as the promoter. Metal‐free conditions, absence of stoichiometric additive, environmentally friendly conditions (H2O/CH3CN, 55 °C, 6 h), broad substrate scope (33 examples, yield up to 92 %) and excellent site‐ and
在碳催化作用下,在氧化石墨烯(GO,10 wt%负载)作为促进剂的情况下,用醇对吲哚进行位点选择性烯丙基和烯丙基脱芳香化反应。无金属的条件,无化学计量的添加剂,环境友好的条件(H 2 O / CH 3 CN,55°C,6 h),广泛的底物范围(33个实例,产率高达92%)以及出色的定点和立体选择性目前的方法。此外,GO功能发挥的共价激活模型得到了光谱,实验和计算证据的证实。还记录了通过简单的酸性处理来回收和再生GO催化剂。
Pd(II)-Catalyzed Highly Regio- and Stereoselective Assembly of C–C Double Bonds: An Efficient Method for the Synthesis of 2,4-Dihalo-1,3,5-trienes from Alkynols
A highly efficient method for the synthesis of 2,4-dihalo-1,3,5-trienes fromalkynols was developed. This chemistry allows access to multiple conjugated double bonds in a single step with high stereoselectivity.