Asymmetric ring-opening of oxabenzonorbornadiene with amines promoted by a chiral iridium-monophosphine catalyst
作者:Renshi Luo、Jianhua Liao、Ling Xie、Wenjun Tang、Albert S. C. Chan
DOI:10.1039/c3cc46009f
日期:——
A new iridium-monophosphine catalyst is found to be efficient for asymmetric ring-opening of benzonorbornadiene with amines, providing a series of chiral substituted dihydronaphthalenes in high yields (up to 98%) and excellent enantioselectivities (>99%).
Iridium-catalyzed asymmetric ring-openingreactions of N-Boc-azabenzonorbornadiene with a number of secondaryamines has been developed for the first time. The reaction gave 1,2-trans-diamine derivatives in moderate to good yields with high enantioselectivity in the presence of 2.5 mol % of [Ir(COD)Cl]2 and 5 mol % of (S)-BINAP. The trans-configuration of the 1,2-diamino products was confirmed by X-ray
Asymmetricring‐openingreactions of N‐Boc‐azabenzonorbornadiene with N‐substituted piperazine nucleophiles in the presence of 5 mol% of [Rh(COD)Cl]2 and 10 mol% of chiral ligand, (R,S)‐PPF‐P‐t‐Bu2, gave the corresponding 1,2‐diamine product in moderate to excellent yields (up to 95%) with reasonable enantiomeric excesses (up to 70% ee). The results showed that the nature of ligands had significant
N -Boc-氮杂苯并降冰片二烯与N-取代的哌嗪亲核试剂在5 mol%[Rh(COD)Cl] 2和10 mol%手性配体(R,S)-PPF-P存在下的不对称开环反应-吨-Bu 2,给相应的1,2-二胺产物在中度至良好的产率(高达95%)以合理的对映体过量(多达70%ee值)。结果表明,配体的性质对产率和对映体过量有显着影响。
Iridium-Catalyzed Asymmetric Ring Opening of Azabicyclic Alkenes by Amines
The enantioselective ring-opening reactions of azabicyclic alkenes with primary and secondary aromaticamine nucleophiles are reported using an iridiumcatalyst generated in situ from 1.5 mol % of [Ir(COD)Cl]2 and 3 mol % of (S)-BINAP. The reaction affords the corresponding trans-1,2-diamine derivatives in moderate to good yields with moderate to high enantioselectivities (up to 97% ee). The trans-configuration
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.