Chiral 2-(2-diphenylphosphinophenyl)-5,6,7,8-tetrahydroquinolines: new P–N ligands for asymmetric catalysis
摘要:
New chiral phosphorus-nitrogen ligands, specifically, 2-(2-diphenylphosphinophenyl)-5,6,7,8-tetrahydroquinolines were prepared and assessed in the enantioselective palladium catalyzed allylic substitution of 1,3-diphenylprop-2-enyl acetate with dimethyl malonate. Enantioselectivity up to 71% was obtained. (C) 2001 Published by Elsevier Science Ltd.
Stereoselective Synthesis of Atropisomeric Bipyridine <i>N,N′</i>-Dioxides by Oxidative Coupling
作者:Yasuaki Fukazawa、Vladimir Yu. Vaganov、Sergei A. Shipilovskikh、Aleksandr E. Rubtsov、Andrei V. Malkov
DOI:10.1021/acs.orglett.9b01687
日期:2019.6.21
Bipyridine N,N′-dioxide is a structural fragment found in many bioactive compounds. Furthermore, chiral analogues secured their place as powerful Lewis base catalysts. The scope of the existing methods for the synthesis of atropisomeric bipyridine N,N′-dioxides is limited. Herein, we present a practical, highly chemo- and stereoselective method for oxidative dimerization of chiral pyridine N-oxides using
Detailed kinetic and computational investigation of the enantio‐ and diastereoselective allylation of aldehydes 1 with allyltrichlorosilanes 5, employing the pyridine N‐oxides METHOX (9) and QUINOX (10) as chiral organocatalysts, indicate that the reaction can proceed through a dissociative (cationic) or associative (neutral) mechanism: METHOX apparently favors a pentacoordinate cationic transition
We herein report the synthesis of 2-(2-methoxyphenyl)-1-azaazulene (8) by a Suzuki–Miyaura cross-coupling reaction between 2-chloro-1-azaazulene and 2-methoxyphenylboronic acid and also by the condensation of tropone and the ylide derived from 1-(o-methoxyphenacyl)pyridinium iodide. Demethylation of 8 afforded the title compound 6. X-ray crystallographic analysis of 6 provided evidence for an intramolecular
A pineno-salen type catalyst for the enantioselective Nozaki–Hiyama–Kishi reaction
作者:Attrimuni P. Dhondge、Ajam C. Shaikh、Chinpiao Chen
DOI:10.1016/j.tetasy.2012.05.012
日期:2012.5
A new class of pineno-salen type ligands 10, 11, 17, 20, 23, and 24 has been developed. The catalyst formed from chromium(II)-10 promotes the enantioselective Nozaki-Hiyama-Kishi allylation of alkyl and aryl aldehydes using allyl bromide. Notably, the asymmetric addition of vinyl halide to benzaldehyde was achieved with 24% ee. (C) 2012 Elsevier Ltd. All rights reserved.
Jeferry, John C.; Maher, John P.; Otter, Carl A., Journal of the Chemical Society, Dalton Transactions, 1995, # 5, p. 819 - 824
作者:Jeferry, John C.、Maher, John P.、Otter, Carl A.、Thornton, Peter、Ward, Michael D.