A novel synthetic approach to fluorine-containing acetylenic compounds based on Nicholas reaction
作者:Tsutomu Konno、Go Nagai、Takashi Ishihara
DOI:10.1016/j.jfluchem.2005.11.009
日期:2006.5
The fluorine-containing dicobalthexacarbonyl complex, prepared readily from γ-fluoroalkylated propargyl acetates and Co2(CO)8, reacted smoothly with various nucleophiles at the propargylic position, followed by oxidative decomplexation under the influence of Fe(NO3)3, to afford fluoroalkylated alkynes bearing various types of alkyl side chains in good to high yields.
Novel synthetic pathway to access trifluoromethylated allenes with 1,3-di- as well as 1,1,3-trisubstitution patterns was developed from a variety of 4,4,4-trifluorobut-2-yn-1-ols which were then transformed into the corresponding vinylic iodides in highly regio- and stereospecific manners, and zinc-mediated β-elimination after trifluoroacetylation of the hydroxyl group eventually realized the formation
Regioselective <i>trans</i>-Carboboration of Propargyl Alcohols
作者:Hongming Jin、Alois Fürstner
DOI:10.1021/acs.orglett.9b01225
日期:2019.5.3
Proper choice of the base allowed trans-diboration of propargylalcohols with B2(pin)2 to evolve into an exquisitely regioselective procedure for net trans-carboboration. The method is modular as to the newly introduced carbon substituent (aryl, methyl, allyl, benzyl, alkynyl), which is invariably placed distal to the −OH group.
A novel method for the generation of 3,3,3-trifluoro-propynyllithium is reported, which involves treatment of trifluoromethyl-substituted enol tosylate, prepared from 1,1-dichloro-3,3,3-trifluoroacetone, with two equivalents of butyllithium. -Palladium-catalyzed coupling reaction of sulfonates of the carbonyl adducts with organozinc reagents gave trifluoromethyl-containing tri- and tetrasubstituted
Remarkable access to fluoroalkylated trisubstituted alkenes via highly stereoselective cobalt-catalyzed hydrosilylation reaction of fluoroalkylated alkynes
Hydrosilylation reaction of various fluoroalkylated alkynes with Et3SiH in the presence of a catalytic amount of Co2(CO)8 was investigated. The hydrosilylation of the alkynes having fluoroalkyl and aryl groups took place smoothly with good regioselectivity (ca. 80:20). In sharp contrast, the reaction of the alkynes having a fluoroalkyl group and a benzyl-type substituent, or various propargyl alcohols gave the corresponding vinylsilanes in an excellent regio- and stereoselective manner. Treatment of the vinylsilanes with various aldehydes in the presence of Zn(OTf)2 and TBAF afforded the coupling products in good yields.