Regiospecific synthesis of symmetrical (1E,3E) 2,3-difluoro-1,4-diphenyl-buta-1,3-dienes via palladium-catalyzed cross-coupling of (Z) 2-bromo-2-fluoroethenylbenzenes in presence of bis(pinacolato)diboron
摘要:
The cross-coupling reaction of (Z) 1-bromo-1-fluoroalkenes catalyzed by PdCl2(PPh3)(2)-2PPh(3) (3%) and CsF in Tetrahydrofuran (THF) in presence of bis(pinacolato)diboron led to (1E,3E) 2,3-difluoro-1,4-disubstituted-buta-1,3-dienes in high yields. (C) 2003 Elsevier B.V. All rights reserved.
Photochemical Generation and Structure of Vinyl Radicals
作者:Theodorus P. M. Goumans、Kaj van Alem、Gerrit Lodder
DOI:10.1002/ejoc.200700882
日期:2008.1
series of E or Z stereoisomeric α-R-substituted bromostyrenes (R = CH3, F or CN) in methanol yields E and/or Z stereoisomeric styrenes, which stem from the corresponding vinylradicals. The results show that the α-Me vinylradical is a rapidly equilibrating, bent structure, while the α-F vinylradical is a stable bent species, in agreement with earlier thermal results. The α-CN vinylradical is assigned
Asymmetric Epoxidation of Fluoroolefins by Chiral Dioxirane. Fluorine Effect on Enantioselectivity
作者:O. Andrea Wong、Yian Shi
DOI:10.1021/jo901553t
日期:2009.11.6
The asymmetricepoxidation of various fluoroolefins has been studied using chiral ketone catalyst, and up to 93% ee was achieved with fructose-derivedketone 1.
已经使用手性酮催化剂研究了各种氟代烯烃的不对称环氧化,果糖衍生的酮1实现了高达 93% 的 ee 。
[EN] 4-OXO-1-(3-SUBSTITUTED PHENYL-1,4-DIHYDRO-1,8-NAPHTHYRIDINE-3-CARBOXAMIDE PHOSPHODIESTERASE-4 INHIBITORS<br/>[FR] 4-OXO-1-(PHENYL-1,4-DIHYDRO-1,8-NAPTHYRIDINE-3-CARBOXAMIDE, A SUBSTITUTION EN 3, UTILES COMME INHIBITEURS DE PHOSPHODIESTERASE-4
申请人:MERCK FROSST CANADA INC
公开号:WO2004048374A1
公开(公告)日:2004-06-10
Compounds represented by Formula (I):or a pharmaceutically acceptable salt thereof, are phosphodiesterase 4 inhibitors useful in the treatment of asthma and inflammation and useful for the enhancement of cognition.
Synthetic and mechanistic aspects of the reactions between bromodifluoromethyltriphenylphosphonium bromide and dibromofluoromethyltriphenylphosphonium bromide and trialkylphosphites
作者:Richard M. Flynn、Donald J. Burton、Denise M. Wiemers
DOI:10.1016/j.jfluchem.2008.04.003
日期:2008.7
exchange process involves the formation of difluorocarbene via dissociation of the intermediate difluoromethylene ylide, capture of the difluorocarbene by the trialkylphosphite to give [(RO)3P+CF2−], which captures bromine followed by dealkylation to the product, bromodifluoromethylphosphonate. The equilibria involved in the multi-step mechanism are all shifted to the phosphonate product by the final dealkylation
A kinetic separation method for the stereoselective preparation of (Z)- and (E)-monofluoroenynes from E/Z mixtures of 1-bromo-1-fluoroolefins
作者:Xin Zhang、Donald J. Burton
DOI:10.1016/s0022-1139(01)00529-2
日期:2001.12
under similar conditions and longer reaction times (48 h) to give pure (E)-monofluoroenynes in excellent yields (78–89%). Thus, E/Z mixtures of 1-bromo-1-fluoroolefins could be kinetically separated into (Z)- and (E)-monofluoroenynes. This methodology provides a simple one-step unequivocal route to the isomerically pure (Z)- and (E)-monofluoroenynes from the readily available 1-bromo-1-fluoroolefins.