Tunable chiral monophosphines as ligands in enantioselective rhodium-catalyzed ring-opening of oxabenzonorbornadienes with amines
摘要:
A new tunable chiral monophosphine was used as a ligand for asymmetric rhodium-catalyzed ring-opening of oxabenzonorbornadiene with amines, providing a series of chiral ring-opened products in high yields (up to 97%) and with high enantioselectivities (>99%).The reaction can be performed at rt to obtain the desired product with high enantioselectivity. (C) 2014 Elsevier Ltd. All rights reserved.
Iridium-Catalyzed Asymmetric Ring-Opening of Oxabenzonorbornadienes with N-Substituted Piperazine Nucleophiles
作者:Wen Yang、Renshi Luo、Dingqiao Yang
DOI:10.3390/molecules201219748
日期:——
Iridium-catalyzed asymmetric ring-opening of oxabenzonorbornadienes with N-substituted piperazines was described. The reaction afforded the corresponding ring-opening products in high yields and moderate enantioselectivities in the presence of 2.5 mol % [Ir(COD)Cl]2 and 5.0 mol % (S)-p-Tol-BINAP. The effects of various chiral bidentate ligands, catalyst loading, solvent, and temperature on the yield and enantioselectivity were also investigated. A plausible mechanism was proposed to account for the formation of the corresponding trans-ring opened products based on the X-ray structure of product 2i.
Iridium-Catalyzed Asymmetric Ring-Opening Reactions of Oxabenzonorbornadienes with Amine Nucleophiles
作者:Dingqiao Yang、Yuhua Long、Junfang Zhang、Heping Zeng、Sanyong Wang、Chunrong Li
DOI:10.1021/om100384q
日期:2010.8.23
We have explored a new iridium-catalyzed ring-openingreaction of oxabenzonorbornadienes with a variety of primary aromatic amine or N-substituted piperazine nucleophiles, affording the corresponding products in excellent yields (up to 99%) with moderate enantioselectivity (25−81% ee). The trans configuration of product 2d was confirmed by X-ray crystallography.
Highly Efficient Rhodium-Catalyzed Asymmetric Ring-Opening Reactions of Oxabenzonorbornadiene with Amine Nucleophiles
作者:Yuhua Long、Shuangqi Zhao、Heping Zeng、Dingqiao Yang
DOI:10.1007/s10562-010-0383-3
日期:2010.8
yields (up to 97%) with excellent enantioselectivities (up to 99%ee).Graphical AbstractRhodium-catalyzed asymmetricring-openingreactions of oxabenzonorbornadienes with aliphatic primary amines and substituted N-phenylpiperazines were investigated. These reactions are featured with the formation of a new carbon-nitrogen bond via an intermolecular allylic displacement of the bridgehead oxygen with amine
A new tunable chiral monophosphine was used as a ligand for asymmetric rhodium-catalyzed ring-opening of oxabenzonorbornadiene with amines, providing a series of chiral ring-opened products in high yields (up to 97%) and with high enantioselectivities (>99%).The reaction can be performed at rt to obtain the desired product with high enantioselectivity. (C) 2014 Elsevier Ltd. All rights reserved.