Geminal‐dichloromethyl derivatives could be efficiently synthesized by the highly chemoselective platinum on carbon‐catalyzed mono‐dechlorination of trichloromethyl substrates in dimethylacetamide (DMA) as a specific solvent at 25 °C under a hydrogen atmosphere.
Copper(I)-Promoted Dechlorinative Surzur−Tanner Rearrangement of 2,2,2-Trichloroethyl Carboxylates
作者:Ram、Nabin Kumar Meher
DOI:10.1021/ol027139u
日期:2003.1.1
[GRAPHICS]2,2,2-Trichloroethyl carboxylates undergo highly efficient dechlorinative Surzur-Tanner rearrangement with 2 equiv of a 1:1 molar mixture of CuCl and bpy in boiling DCE to give 1-chloroethenyl carboxylates in which copper appears to play an important role, probably by coordinating the initial radical or as a Lewis acid catalyst.
US4450309A
申请人:——
公开号:US4450309A
公开(公告)日:1984-05-22
Efficient partial hydrogenation of trichloromethyl to gem-dichloromethyl groups in platinum on carbon-catalyzed system
Effect of <i>ortho</i>
substituents on carbonyl carbon <sup>13</sup>
C NMR chemical shifts in substituted phenyl benzoates
作者:Vilve Nummert、Mare Piirsalu、Vahur Mäemets、Signe Vahur、Ilmar A. Koppel
DOI:10.1002/poc.1569
日期:2009.12
an upfield shift or shielding of the carbonylcarbon, while the electron‐donating substituents had an opposite effect. Because of the sterical consequences, ortho substituents revealed a deshielding effect on the 13C NMR chemicalshift of the carbonylcarbon. For all the meta‐ and para‐substituted esters, the reverse substituent‐induced inductive and resonance effects (ρI < 0, ρR < 0) were found to
记录了37种邻,间和对位取代的苯甲酸苯酯的13 C NMR光谱,这些苯甲酸在苯甲酰基和苯基部分中含有取代基,4个邻取代的甲基和5个乙基苯甲酸酯以及9个R取代的烷基苯甲酸酯。的影响邻上的羰基碳的取代基13 C NMR化学位移,δ CO,发现通过含有电感性的,线性多元回归方程来描述σ我,共振,σ ° - [R ,和位阻,ê,或υ取代基常数。对于所有的邻位含有取代基的酰基部分,以及所述苯基部分,所述取代基诱导的反向电感效应取代的酯(ρ我 <0),正常共振效应(ρ [R > 0),和负位阻效应(δ邻 <0)与Ë观察。在苯基部分有邻位取代基的情况下,共振效应可忽略不计。由于感应效应,邻位吸电子取代基表现出对羰基碳的高场移位或屏蔽,而给电子取代基具有相反的作用。由于空间上的后果,邻位取代基显示出对羰基碳的13 C NMR化学位移的屏蔽作用。对于所有的间位和对位取代的酯,反向取代基引起的电感和共振效应(ρ我 <0,ρ