Enthalpy versus Entropy in Chlorocarbene/Alkene Addition Reactions
作者:Robert A. Moss、Lei Wang、Min Zhang、Christopher Skalit、Karsten Krogh-Jespersen
DOI:10.1021/ja8005226
日期:2008.4.1
We report the first measured activation parameters for the additions of CCl2 and CClF to simple alkenes and demonstrate the existence of enthalpic barriers for CCl2 additions to cyclohexene and 1-hexene. With these two alkenes, additions of PhCCl are "dominated" by entropic contributions to deltaG++ and additions of CCl2 display comparable contributions of deltaH++ and deltaS++, while CClF additions
Laser Flash Photolysis Study of Chlorofluorocarbene
作者:Eric M. Tippmann、Matthew S. Platz
DOI:10.1021/jp0345598
日期:2003.10.1
6]decadiene-2,4 (1) was synthesized. Continuous photolysis of 1 (300 nm) generates chlorofluorocarbene 2, which can be intercepted with tetramethylethylene (TME) to form the expected cyclopropane 3. Laser flashphotolysis (LFP) of 1 (308 nm) in cyclohexane at ambient temperature does not result in the direct detection of 2 by time-resolved UV−vis spectroscopy. However, LFP of 1 in the presence of pyridine
Generation of chlorofluorocarbene by dehalogenation of fluorotrichloromethane with reduced titanium. A new synthesis of 1-chloro-1-fluorocyclopropanes.
作者:William R. Dolbier、Conrad R. Burkholder
DOI:10.1016/s0040-4039(00)82445-4
日期:——
Reaction of fluorotrichloromethane with reducedtitanium at 0° produces chlorofluorocarbene which adds to alkenes, giving 1-chloro-1-fluorocyclopropanes in good yield
cost-effective and an environmentally benign strategy for the safe consumption/destruction of the ozone depleting potential of the reagent. In this report, we present a novel method for in situ Grignardreaction using magnesium powder and CFCl3 for synthesis of dichlorofluoromethyl aromatic alcohols.