Preparation of Alkylmagnesium Reagents from Alkenes through Hydroboration and Boron-Magnesium Exchange
作者:Markus A. Reichle、Bernhard Breit
DOI:10.1002/anie.201201704
日期:2012.6.4
Tolerant: Alkylmagnesium reagents can be synthesized from alkenes through a sequence of hydroboration and subsequent boron–magnesium exchange using a method that tolerates different functional groups (see scheme). The resulting alkylmagnesium reagents can be used in carbon–carbon bond forming reactions, such as alkylation reactions or transition‐metal‐catalyzed cross‐coupling reactions.
The reactions of trialkylboranes or B-alkyl-9-BBN with aryl and 1-alkenyl halides take place readily in the presence of PdCl2(dppf) and sodium hydroxide or methoxide to afford alkylated arenes and alkenes in excellent yields.
<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
<i>N</i>-Acylsaccharins as Amide-Based Arylating Reagents via Chemoselective N–C Cleavage: Pd-Catalyzed Decarbonylative Heck Reaction
作者:Chengwei Liu、Guangrong Meng、Michal Szostak
DOI:10.1021/acs.joc.6b02294
日期:2016.12.2
decarbonylative Heckreaction of amides by chemoselective N–C activation using N-acylsaccharins as coupling partners has been accomplished. These studies represent only the second example of amide-Heck reactions reported to date. A broad range of electronically diverse amide and olefin coupling partners is amenable to this transformation. Orthogonal site-selective Heckcross-couplings by C–Br/N–C cleavage
From vinyl sulfides, sulfoxides and sulfones to vinyl zirconocene derivatives
作者:Shahera Farhat、Irena Zouev、Ilan Marek
DOI:10.1016/j.tet.2003.08.074
日期:2004.2
An easy and straightforward new method for the preparation of sp2 zirconocene derivatives from a wide range of heterosubstituted alkenes such as vinyl sulfides, sulfoxides and sulfones is described. In all cases, a complete isomerization of the stereochemistry is observed and only the E-isomer is obtained. The reactivity of the resulting vinylic organometallic can be increased by a transmetalation