Asymmetric synthesis of atropisomeric pyrazole <i>via</i> an enantioselective reaction of azonaphthalene with pyrazolone
作者:Huijun Yuan、Yao Li、Hanhui Zhao、Zhihong Yang、Xin Li、Wenjun Li
DOI:10.1039/c9cc06360a
日期:——
The first catalytic asymmetricreaction of azonaphthalene with pyrazolone has been established. A wide range of axially chiral pyrazole derivatives have been achieved in good yields (68–99%) with excellent enantioselectivities (83–98% ee) by utilizing chiral phosphoric acid as a catalyst. This strategy provides an efficient and facile approach for the construction of axially chiral pyrazole derivatives
Triton-B-Catalyzed, Efficient, One-Pot Synthesis of Carbazates Through Alcoholic Tosylates
作者:Devdutt Chaturvedi、Amit K. Chaturvedi、Nisha Mishra、Virendra Mishra
DOI:10.1080/00397910802269259
日期:2008.10.28
A quick, efficient, one-pot synthesis of carbazates was accomplished in high yields by the reaction of various tosylates of primary, secondary, and tert alcohols, with a variety of substituted hydrazines using the benzyltrimethylammonium hydroxide (Triton-B)/CO2 system. The reaction conditions are mild with simpler workup procedures than the reported methods.
Triton-B catalyzed, efficient one-pot synthesis of carbazates
作者:Devdutt Chaturvedi、Amit K. Chaturvedi、Nisha Mishra、Virendra Mishra
DOI:10.1007/s00706-008-0955-8
日期:2008.12
A quick and efficient, one-pot synthesis of carbazates was accomplished in high yields by the reaction of various primary, secondary, and tertiary alkyl halides with a variety of substituted hydrazines using the benzyltrimethylammonium hydroxide (Triton-B)/CO2 system. The reaction conditions are mild with simpler work-up procedures than the reported methods.