首次实现了β,β-二芳基不饱和膦酸酯的不对称氢化,用于在Rh-( R , R )-f-spiroPhos 络合物催化下合成具有优异对映选择性(高达99.9% ee)的β,β-二芳基手性膦酸酯. 此外,该催化剂对 β-芳基-β-烷基不饱和膦酸酯也表现出相当优异的性能,提供相应的手性膦酸酯,其 ee 值高达 99.9%。这种方法为不对称合成手性膦酸盐提供了一种直接的途径。
Enantioselective Reduction of Electrophilic C?C Bonds with sodium tetrahydroborate and ?semicorrin? cobalt catalysts
作者:Marian Misun、Andreas Pfaltz
DOI:10.1002/hlca.19960790404
日期:1996.6.26
‘Semicorrin’ cobaltcomplexes, prepared in situ from cobalt(II) chloride and the corresponding ligands, are efficient catalysts for the enantioselective reduction of electrophilic CC bonds with NaBH4. The best selectivities (> 90% ee) are achieved with α,β-unsaturated carboxamides and carboxylates. Analogous α,β-unsaturated nitriles, sulfones, and phosphonates afford enantiomeric excesses of 50–70%
Enantioselective synthesis of optically active alkylphosphonates via Rh-catalyzed asymmetric hydrogenation of β-substituted α,β-unsaturated phosphonates
The Rh-catalyzed asymmetric hydrogenation of beta-substituted alpha,beta-unsaturated phosphonates using (S-c,S-p)-WalPhos as the chiral ligand is reported, in which a wide range of optically active beta-substituted alkylphosphonates were obtained in good yields and with good to excellent enantioselectivities (86-98% ee). In contrast to the Rh/(R-c,S-a)-FAPhos system previously reported by us, the present catalytic system shows a wider substrate scope, and can perform the hydrogenation under milder reaction conditions. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.
Rh-ImiFerroPhos complexes catalyzed asymmetric hydrogenation of β-substituted α,β-unsaturated hosphonates
A series of chiral ferrocenyl diphosphine ligands (ImiFerroPhos ligands) has been applied to the hydrogenation of beta-substituted alpha,beta-unsaturated phosphonates to generate a range of optically active beta-substituted alkylphosphonates in good yields with good enantioselectivity (up to 92% ee) under mild reaction conditions. (C) 2014, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.
Cu-catalyzed asymmetric conjugate reduction of β-substituted α,β-unsaturated phosphonates: an efficient synthesis of optically active β-stereogenic alkylphosphonates
A series of chiral alkylphosphonates bearing beta-stereogenic center were synthesized in good enantioselectivities (up to 95% ee) via the CuH-catalyzed asymmetric conjugate reduction of beta-substituted alpha,beta-unsaturated phosphonates under optimal conditions using Cu(OAc)(2)center dot H2O as the copper source, (R)-SEGPHOS as the ligand. PMHS as the siloxane, and t-BuOH as the additive. (C) 2009 Elsevier Ltd. All rights reserved.
A New and Facile Synthetic Route to 1-Alkyl-2-Oxopropylphosphonates : 1-Alkylation with Subsequent Ozonolysis of 2-Methyl Allylic Phosphonates