- 1,2-Migration in rhodium(II) carbene transfer reaction: Remarkable steric effect on migratory aptitude
-
A series of diazo carbonyl compounds bearing different substituents have been prepared in order to investigate the steric effect in 1,2-migration reaction of rhodium(II) carbene. Through the investigation on the diazo decomposition of these compounds with Rh2(OAc)4, it was found that the steric effect could dramatically influence the migratory aptitude. In many cases, the steric effect could override the inherent electronic effect of the substituent.
- Xiao, Fengping,Wang, Jianbo
-
p. 5789 - 5791
(2007/10/03)
-
- Investigation of the transition-metal- and acid-catalyzed reactions of β-(N-tosyl)amino diazo carbonyl compounds
-
A series of β-(N-tosyl)amino diazo carbonyl compounds have been prepared by nucleophilic condensation of N-tosylimines with acyldiazomethanes. The diazo decomposition of these diazo carbonyl compounds under various catalytic conditions, including Rh(II) carboxylates, Cu(I) and Cu(II) complexes, PhCO2Ag/Et3N, TsOH, and SnCl2·2H2O, has been investigated. It was found that, in most cases, the diazo decomposition gave preferentially 1,2-aryl migration product, but 1,2-hydride migration predominated when PhCO2Ag/Et3N was the catalytic system. Hammett correlation has been applied in the analysis of the electronic effects of 1,2-aryl migration. The factors that govern the migratory preference and the mechanistic aspects of the reaction are discussed.
- Jiang, Nan,Ma, Zhihua,Qu, Zhaohui,Xing, Xiaoyu,Xie, Linfeng,Wang, Jianbo
-
p. 893 - 900
(2007/10/03)
-
- DBU-promoted condensation of acyldiazomethanes to aldehydes and imines under catalytic conditions
-
The condensation of acyldiazomethanes to aldehydes and imines can be promoted with catalytic amount of DBU. The condensation gives β-hydroxy α-diazo carbonyl compounds or β-amino α-diazo carbonyl compounds in high yields.
- Jiang, Nan,Wang, Jianbo
-
p. 1285 - 1287
(2007/10/03)
-