The first phosphine-catalyzed highly enantioselective [3 + 3] cycloaddition of Morita-Baylis-Hillman carbonates with C,N-cyclicazomethineimines is described. Using a spirocyclic chiral phosphine as the catalyst, a novel class of pharmaceutically interesting 4,6,7,11b-tetrahydro-1H-pyridazino[6,1-a]iso-quinoline derivatives were obtained in high yields with good to excellent diastereoselectivities
Chiral Phosphoric Acid-Catalyzed Enantioselective Formal [3+2] Cycloaddition of Azomethine Imines with Enecarbamates
作者:Yang Wang、Qian Wang、Jieping Zhu
DOI:10.1002/chem.201601548
日期:2016.6.6
The first catalytic asymmetric inverse electron demand 1,3‐dipolar cycloaddition of azomethine imines with enecarbamates has been developed. Isoquinoline‐fused pyrazolidines containing two or three contiguous stereogenic centers were obtained in high yields with excellent regio‐, diastereo‐, and enantioselectivities. The pyrazolidine ring can be opened to install an aminal, α‐amino nitrile, or homoallylamine
CuBr2 catalyzed bromination/oxidation of isochromans to benzaldehyde derivatives
作者:Mei-Yan Zhou、Shan-Shan Kong、Ling-Qiong Zhang、Ming Zhao、Jin-Ao Duan、Zhen Ou-yang、Min Wang
DOI:10.1016/j.tetlet.2013.05.078
日期:2013.7
A series of isochromans were oxidized and brominated by using 1.2 equiv of CuBr2 in CH3CN at reflux to give the corresponding bromo benzaldehydes in moderate yields. A plausible mechanism for this transformation has been suggested. (C) 2013 Elsevier Ltd. All rights reserved.