Stereoselective Synthesis of Trisubstituted Alkenes through Sequential Iron-Catalyzed Reductive<i>anti</i>-Carbozincation of Terminal Alkynes and Base-Metal-Catalyzed Negishi Cross-Coupling
作者:Chi Wai Cheung、Xile Hu
DOI:10.1002/chem.201504049
日期:2015.12.7
stereoselective synthesis of trisubstituted alkenes is challenging. Here, we show that an iron‐catalyzed anti‐selective carbozincation of terminal alkynes can be combined with a base‐metal‐catalyzed cross‐coupling to prepare trisubstituted alkenes in a one‐pot reaction and with high regio‐ and stereocontrol. Cu‐, Ni‐, and Co‐based catalytic systems are developed for the coupling of sp‐, sp2‐, and sp3‐hybridized
A palladium-catalyzed stereospecific alkylation of allylamines with primary and secondaryalkyliodides is described. Isoquinoline-1-carboxamide (IQA) acts as directing group to generate multisubstituted olefin products in cis configuration in moderate to good yields. Mechanistic studies suggest that alkenyl C–H bond activation is the rate-determining step.
<i>Z</i>-Selective Olefin Synthesis via Iron-Catalyzed Reductive Coupling of Alkyl Halides with Terminal Arylalkynes
作者:Chi Wai Cheung、Fedor E. Zhurkin、Xile Hu
DOI:10.1021/jacs.5b01784
日期:2015.4.22
Selective catalytic synthesis of Z-olefins has been challenging. Here we describe a method to produce 1,2-disubstituted olefins in high Z selectivity via reductive cross-coupling of alkylhalides with terminal arylalkynes. The method employs inexpensive and nontoxic catalyst (iron(II) bromide) and reductant (zinc). The substrate scope encompasses primary, secondary, and tertiaryalkylhalides, and
Transition Metal Free Stannylation of Alkyl Halides: The Rapid Synthesis of Alkyltrimethylstannanes
作者:Songyi Li、Chang Lian、Guanglu Yue、Jianning Zhang、Di Qiu、Fanyang Mo
DOI:10.1021/acs.joc.1c03135
日期:2022.3.18
A transition metal free stannylation reaction of alkyl bromides and iodides with hexamethyldistannane has been developed. This protocol is operationally convenient and features a rapid reaction and good functional group tolerance. A wide range of functionalized primary and secondary alkyl and benzyl trimethyl stannanes are prepared in moderate to excellent yields. The success of the gram-scale procedure
Copper-catalyzed synthesis of aryl and alkyl trifluoromethyl sulfides using CF3SiMe3 and Na2S2O3 as –SCF3 source
作者:Wei Zhong、Xiaoming Liu
DOI:10.1016/j.tetlet.2014.07.039
日期:2014.8
universal and efficient Cu(I)-catalyzed synthesis of aryl and alkyl trifluoromethyl sulfides has been developed. In this catalytic system, S-aryl or S-alkyl sulfothioate (I or II) proved to be the key intermediate. Substrates bearing groups of I, Br, Cl, OTs, and OMs on the aryl carbon and no matter electron-withdrawing and electron-donating substitutions on the aromatic ring could afford good to excellent