Isomeric fluorinated α‐bromoenones react with dinucleophilic β‐mercaptoalcohols in CH2Cl2 at room temperature in the presence of Et3N in a multistep process. Depending on the position of the CF3 group, different O,S‐heterocycles or non‐cyclic products were obtained. With 3‐bromo‐1,1,1‐trifluorobut‐3‐en‐2‐ones derivatives of 1,4‐oxathianes were formed, but isomeric2‐bromo‐4,4,4‐trifluorobut‐2‐en‐1‐ones
Highly Enantioselective [3 + 2] Annulation of 3-Butynoates with β-Trifluoromethyl Enones Promoted by an Amine−Phosphine Binary Catalytic System
作者:Huanzhen Ni、Yee Lin Wong、Mingyue Wu、Zhaobin Han、Kuiling Ding、Yixin Lu
DOI:10.1021/acs.orglett.0c00681
日期:2020.3.20
enantioselectivities. A unique catalytic system consisting of a simple amine and a chiralphosphine was devised, and the synergistic play of Lewis basic amine and phosphine was crucial for alkyne isomerization and subsequent cyclization. The protocol disclosed herein allows facile activation of 3-butynoates in phosphine-mediated asymmetric transformations.
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.
Smooth isomerization of 4,4,4-trifluorinated propargylic alcohols 1 opened a new and convenient route to readily get access to the corresponding α,β-unsaturated ketones 4 just by heating a THF solution in the presence of Et3N.
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.