34052-44-3Relevant academic research and scientific papers
Stereoselective Synthesis of Trisubstituted Alkenes through Sequential Iron-Catalyzed Reductive anti-Carbozincation of Terminal Alkynes and Base-Metal-Catalyzed Negishi Cross-Coupling
Cheung, Chi Wai,Hu, Xile
, p. 18439 - 18444 (2015/12/24)
The 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 carbon electrophiles, respectively. The method encompasses a large substrate scope, as various alkynyl, aryl, alkenyl, acyl, and alkyl halides are suitable coupling partners. Compared with conventional carbometalation reactions of alkynes, the current method avoids pre-made organometallic reagents and has a distinct stereoselectivity. One-pot reaction: A wide range of trisubstituted olefins can be stereoselectively prepared by a sequential iron-catalyzed anti-carbozincation of terminal arylalkynes with alkyl iodides followed by copper-, nickel-, and cobalt-catalyzed cross-couplings with various sp-, sp2-, and sp3-carbon electrophiles, respectively (see scheme; DMA=dimethylacetamide, bipy=2,2-bipyridine, cod=1,5-cyclooctadiene, TMEDA=N,N,N′,N′-tetramethylethylenediamine).
DBU/DMSO Promoted Dehydrobromination of 1,1-Dibromoolefins. A General Synthesis of 1-Bromoaromatic Alkynes under mild Conditions
Ratovelomanana, Victorin,Rollin, Yolande,Gebehenne, Catherine,Gosmini, Corinne,Perichon, Jacques
, p. 4777 - 4780 (2007/10/02)
A new procedure for the synthesis of 1-bromoalkynes by DMSO/DBU induced dehydrobromination of 1,1-dibromoethylenes under mild conditions is described.
