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.
A Simple, Two-Step, Site-Specific Preparation of Fluorinated Naphthalene and Phenanthrene Derivatives from Fluorobromo-Substituted Alkenes
作者:Yi Wang、Jianjun Xu、Donald J. Burton
DOI:10.1021/jo061305k
日期:2006.9.1
two-step procedure for the site-specific preparation of fluorinated naphthalene and phenanthrenederivatives is described. The Sonogashira reaction of bromofluoro-substituted alkenes with terminal alkynes, followed by base-catalyzed cyclization in refluxing N-methyl-2-pyrrolidinone (NMP), affords the corresponding fluorinated naphthalene and phenanthrenederivatives in good yields.
The reactions of fluorinated ylide, generated from tris(dimethylamino)phosphine and tribromofluoromethane, with simple aldehydes and reactive ketones gave the expected Wittig reaction products. How...
A halon-free method for the synthesis of ‑bromofluoroolefins utilizing ethyldibromofluoro-acetate is disclosed via a Wittigtypereaction. The reaction system takes advantage of inexpensive and readily available reagents. The method was applied to a wide variety of aryl aldehydes. Both electron donating and electron withdrawing moieties on the aryl ring were tolerated and the desired olefin products
Synthesis of 1-bromo-1-fluoroolefins was achieved in good yields via a Wittig reaction promoted by diethylzinc, even with nonactivated aldehydes and ketones as starting materials.