Synthesis of chiral sulfonamide/Schiff base ligands
摘要:
We report a facile two step synthesis of chiral ligands for bonding to transition-metals. The ligands are easily prepared from trans-1,2-diaminocycrohexane by reaction with sulfonyl chlorides to give amino-sulfonamide compounds. These intermediates are then condensed with salicylaldehyde derivatives to provide sulfonamide/Schiff base compounds which represent a new class of chiral ligands. (C) 1998 Elsevier Science Ltd. All rights reserved.
Asymmetric Synthesis of Polysubstituted 4-Amino- and 3,4-Diaminochromanes with a Chiral Multifunctional Organocatalyst
作者:Wenduan Hou、Bo Zheng、Jun Chen、Yungui Peng
DOI:10.1021/ol300798t
日期:2012.5.4
A series of multifunctional catalysts with two chiral diaminocyclohexane units were developed and successfully applied in the asymmetricoxa-Michael–aza-Henrycascadereaction of salicylaldimines with nitroolefins. This approach provides a simple and efficient entry to polysubstituted chiral 4-aminobenzopyrans with three consecutive stereocenters and in high yield (up to 97%) with excellent stereoselectivity
This work disclosed a highly enantioselective hydrogenation of non-ortho-substituted 2-pyridyl arylketones via Ir/f-diaphos catalysis. This catalytic system allows for full control over the configuration of the stereocenter, affording two enantiomers of the desired products with extremely high enantioselectivity (up to >99% ee in most cases) and excellent reactivity (TON of up to 19600, TOF of 1633
The iridium/f-diaphos L1, L5 or L12 catalyzed asymmetric hydrogenation of 2-imidazolyl aryl/alkyl ketones to afford two enantiomers of the desired chiral alcohols with high conversions (up to 99% yield) and moderate to excellent enantioselectivities (61% - >99% ee) was realized for the first time. This protocol could be easily conducted on a gram-scale with a TON of 9700.
铱/ f-二磷L1、L5或L12催化 2-咪唑基芳基/烷基酮的不对称氢化,得到所需手性醇的两种对映异构体,具有高转化率(高达 99% 的产率)和中等至优异的对映选择性(61% - >99% ee ) 首次实现。该协议可以在 TON 为 9700 的克级上轻松执行。
Enantioselective Reaction of 2<i>H</i>
-Azirines with Phosphite Using Chiral Bis(imidazoline)/Zinc(II) Catalysts
作者:Shuichi Nakamura、Daiki Hayama
DOI:10.1002/anie.201704133
日期:2017.7.17
The first highly enantioselective nucleophilic addition reaction of phosphites with 2H‐azirines has been developed. The reaction was applied to various 3‐substituted 2H‐azirines using novel chiralbis(imidazoline)/ZnII catalysts to afford products in good yield with high enantioselectivity. The transformation of the obtained optically active aziridines showed that 2H‐azirines act as either α,β‐ or
Synthesis of chiral sulfonamide/Schiff base ligands
作者:Jaume Balsells、Lupe Mejorado、Mimi Phillips、Fernando Ortega、Gerardo Aguirre、Ratnasamy Somanathan、Patrick J. Walsh
DOI:10.1016/s0957-4166(98)00431-5
日期:1998.12
We report a facile two step synthesis of chiral ligands for bonding to transition-metals. The ligands are easily prepared from trans-1,2-diaminocycrohexane by reaction with sulfonyl chlorides to give amino-sulfonamide compounds. These intermediates are then condensed with salicylaldehyde derivatives to provide sulfonamide/Schiff base compounds which represent a new class of chiral ligands. (C) 1998 Elsevier Science Ltd. All rights reserved.