Alkylzirconation of alkynes catalyzed by triphenylcarbenium tetrakis(pentafluorophenyl)borate
摘要:
[(C6H5)(3)C](+)[B(C6F5)(4)](-) effectively catalyzes the alkylmetallation of alkynes by using the alkylzirconium species, which is generated by the hydrozirconation of alkenes. (C) 1999 Elsevier Science Ltd. All rights reserved.
A regio- and stereoselective synthesis of trisubstituted alkenes via gold(i)-catalyzed hydrophosphoryloxylation of haloalkynes
作者:Bathoju Chandra Chary、Sunggak Kim、Doosup Shin、Phil Ho Lee
DOI:10.1039/c1cc12052b
日期:——
A new stereoselective synthesis of trisubstitutedalkenes is developed. Hydrophosphoryloxylation of haloalkynes provides Z-alkenyl halophosphates, which undergo Pd-catalyzed consecutive cross-coupling reactions to afford regio- and stereodefinedtrisubstitutedalkenes.
Cross-Coupling of Alkenyl/Aryl Carboxylates with Grignard Reagent via Fe-Catalyzed C−O Bond Activation
作者:Bi-Jie Li、Li Xu、Zhen-Hua Wu、Bing-Tao Guan、Chang-Liang Sun、Bi-Qin Wang、Zhang-Jie Shi
DOI:10.1021/ja907281f
日期:2009.10.21
Iron-catalyzed cross-coupling of alkenyl/aryl carboxylates with primary alkyl Grignard reagent was described. This reaction brought a new family of electrophiles to iron catalysis. The combination of an inexpensive carboxylate electrophile and an iron catalyst would generate ample advantages.
Treatment of homopropargylic alcohol derivatives or phenylacetylene compounds with phenylmagnesium bromide in the presence of a catalytic amount of manganese(II) chloride afforded phenylated products in good yields with high regio- and stereoselectivities.
在催化量的氯化锰 (II) 存在下,用溴化苯基镁处理高炔丙醇衍生物或苯乙炔化合物,以高产率和高区域选择性和立体选择性提供苯化产物。
Carbolithiation of Diphenylacetylene as a Stereoselective Route to (<i>Z</i>)-Tamoxifen and Related Tetrasubstituted Olefins
作者:Neola F. McKinley、Donal F. O'Shea
DOI:10.1021/jo061949s
日期:2006.12.1
Carbolithiation of diphenylacetylene can be exploited to generate (E)-1-lithio-1,2-diphenylalkyl-1-enes which can be reacted in situ with triisopropylborate to stereoselectively provide (E)-1,2-diphenyl-1-alkylene boronic acids. These tetrasubstituted vinylboronic acids served as versatile intermediates for the generation of tetrasubstituted olefins with retention of stereochemistry. The application
[GRAPHICS]Arylmagnesiation of unfunctionalized alkynes in the presence of catalytic amounts of chromium(II) chloride and pivalic acid proceeds with high stereoselectivity. The alkenylmagnesium intermediate reacts with various electrophiles to afford the corresponding tetrasubstituted olefins in good yields.