Vitamin B<sub>12</sub>Catalyzed Radical Cyclizations of Arylalkenes
作者:Wilfred A. van der Donk、Chris M. McGinley、Heather A. Relyea
DOI:10.1055/s-2005-923588
日期:——
The use of vitamin B 1 2 for synthetic organic transformations has been extensively studied. Herein, we report the intramolecular cyclization reaction of a series of arylalkene substrates catalyzed by vitamin B 1 2 . Thesereactions proceed in good yields in environmentally benign solvents and do not require the use of a toxic heavy metal catalyst. Variation of the reaction pH can predictably alter
已经广泛研究了维生素 B 1 2 在合成有机转化中的应用。在此,我们报告了一系列由维生素 B 1 2 催化的芳基烯烃底物的分子内环化反应。这些反应在环境友好的溶剂中以良好的产率进行,并且不需要使用有毒的重金属催化剂。反应 pH 值的变化可以预测地改变产物分布。
Mechanistic Investigation of a Novel Vitamin B<sub>12</sub>-Catalyzed Carbon−Carbon Bond Forming Reaction, the Reductive Dimerization of Arylalkenes
作者:Justin Shey、Chris M. McGinley、Kevin M. McCauley、Anthony S. Dearth、Brian T. Young、Wilfred A. van der Donk
DOI:10.1021/jo0160470
日期:2002.2.1
reaction to the active Co(I) state, and by removing Co(II) it also prevents the nonproductive recombination of alkyl radicals with cob(II)alamin. The mechanism of the formation of benzylic radicals from arylalkenes and cob(I)alamin poses an interesting problem. The results with a one-electron transfer probe indicate that radical generation is not likely to involve an electrontransfer. Several alternative
Initiating radical cyclizations by H transfer from transition metals
作者:John Hartung、Mary E. Pulling、Deborah M. Smith、David X. Yang、Jack R. Norton
DOI:10.1016/j.tet.2008.10.030
日期:2008.12
diphosphine) can be used to initiate radicalcyclizations by transferring H to activated terminal olefins. CpCr(CO)3H can catalyze reductive cyclizations, with H2 as the ultimate reductant. Appropriate substrates can be assembled by the Morita–Baylis–Hillman reaction of methyl acrylate with an aldehyde. Six- as well as five-membered rings can be formed, and a tandem cyclization to decalin can be effected.