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。
Iron-Promoted Difunctionalization of Alkenes by Phenylselenylation/1,2-Aryl Migration
作者:Ping Wu、Kaikai Wu、Liandi Wang、Zhengkun Yu
DOI:10.1021/acs.orglett.7b02751
日期:2017.10.6
Iron-promoted difunctionalization of α,α-diaryl and α-aryl-α-alkyl allylic alcohols has been efficiently achieved by means of N-(phenylseleno)phthalimide (N-PSP) under mild conditions. An in situ generated phenylselenium cation (PhSe+) was added to the olefinic C═C bond to initiate the regioselective phenylselenylation with concomitant 1,2-aryl migration, following a migration preference contrary to
Stoichiometric Release of SO2 from Adducts: Application to the Direct Synthesis of Protected Dienes
作者:Laurent Bischoff、Ludovic Martial
DOI:10.1055/s-0034-1380508
日期:——
The in situ, stoichiometric release of SO2 was studied from DABSO (DABCO adduct with SO2) and DMAP adduct. When involved in cheletropic additions, free SO2 released by this technique proved much more reactive than its adducts. Some examples of applications towards the direct synthesis of protected dienes from allylic alcohols are given.
Regioselective and Stereospecific Rhodium-Catalyzed Allylic Cyanomethylation with an Acetonitrile Equivalent: Construction of Acyclic β-Quaternary Stereogenic Nitriles
作者:Mai-Jan Tom、P. Andrew Evans
DOI:10.1021/jacs.0c02316
日期:2020.7.15
A highlyregioselective and stereospecific rhodium-catalyzed cyanomethylation of tertiary allyliccarbonates for the construction of acyclic β-quaternary stereogenic nitriles is described. This protocol represents the first example of a metal-catalyzed allylicsubstitution reaction using a triorganosilyl-stabilized acetonitrile anion, which permits access to several carbonyl derivatives that are challenging