Coupling of Trifluoroacetaldehyde <i>N</i>-Triftosylhydrazone with Organoboronic Acids for the Synthesis of <i>gem</i>-Difluoroalkenes
作者:Yu Ma、Bhoomireddy Rajendra Prasad Reddy、Xihe Bi
DOI:10.1021/acs.orglett.9b03740
日期:2019.12.20
synthesis of alkyl gem-difluoroalkenes remains a difficult task in organic synthesis. Here, we report a general and efficient approach for tackling this problem by gem-difluoroolefination of trifluoroacetaldehyde N-triftosylhydrazone with organoboronic acids. This protocol is operationally simple, free of transition metals, and suitable for a broad range of organoboronic acids. Moreover, the utility
Reactions of 1,1-difluoro-1-olefins with electrophilic reagents
作者:Minoru Suda
DOI:10.1016/0040-4039(80)80127-4
日期:1980.1
1,1-Difluoro-1-olefins react smoothly with electrophilicreagents such as bromine and acid chloride-Lewis acid at room temperature producing the addition products.
CONVENIENT PROCEDURES FOR CONVERSION OF CARBONYL COMPOUNDS TO<i>gem</i>-DIFLUOROOLEFINS AND THEIR SELECTIVE REDUCTIONS TO MONOFLUOROOLEFINS
作者:Sei-ichi Hayashi、Takeshi Nakai、Nobuo Ishikawa、Donald J. Burton、Douglas G. Naae、H. S. Kesling
DOI:10.1246/cl.1979.983
日期:1979.8.5
triphenylphosphine, and aldehydes in the presence of zinc dust affords good yields of gem-difiuoroolefins. Reduction of the difluoroolefins gives selectively the corresponding monofluoro-olefins in excellent yields. The scope and limitation of these procedures are described and compared with those of previous methods.
DEFLUORINATIVE COUPLING REACTIONS OF<i>gem</i>-DIFLUOROOLEFINS WITH ORGANOLITHIUM REAGENTS. NOVEL, FACILE METHODS FOR CHAIN ELONGATIONS OF ALDEHYDES LEADING TO AMIDES, ACETYLENES, AND KETONES
作者:Sei-ichi Hayashi、Takeshi Nakai、Nobuo Ishikawa
DOI:10.1246/cl.1980.935
日期:1980.8.5
Three types of coupling reactions of gem-difluoroolefins derived easily from aldehydes with lithium reagents (R′Li and R′2NLi) are described which constitute the facile procedures for conversions of aldehydes (RCHO) to amides (RCH2CONR′2), acetylenes (R–C≡C–R′), and ketones (RCH2COR′).
Synthesis of Trifluoromethyl-Substituted Cyclopropanes via Sequential Kharasch–Dehalogenation Reactions
作者:Julie Risse、Mariano A. Fernández-Zúmel、Yanouk Cudré、Kay Severin
DOI:10.1021/ol3011369
日期:2012.6.15
A two-step process for the synthesis of trifluoromethyl-substituted cyclopropanes is described. Halothane, an anesthetic agent, is added to olefins in a ruthenium-catalyzedKharaschreaction. The resulting 1,3-dihalides are converted into cyclopropanes by dehalogenation with magnesium. This procedure represents an alternative to metal-catalyzed cyclopropanations involving trifluoromethyl diazomethane