The first enantioselective [3+2] cycloaddition of epoxides to arylisocyanates: asymmetric synthesis of chiral oxazolidinone phosphonates
摘要:
A [3+2] cycloaddition of diethyl 1 2-oxiranephosphonate to aryl isocyanates catalyzed by lanthanide cations is described The reaction is highly regioselective and 5-substituted 2-oxazolidinone phosphonates are obtained with a regioselectivity greater than 95 5 with respect to the 4-substituted regioisomer and in up to 84% yield When 20 mol % of Pybox-Yb3+ is used as a catalyst enantiomerically enriched products are obtained in up to 75% ee depending on the reaction conditions and the nature of the isocyanate Low temperatures benefit asymmetric induction but have an adverse effect on the regioselectivity for para-substituted aryl isocyanates (C) 2010 Elsevier Ltd All rights reserved
Enzymatic synthesis of phosphocarnitine, phosphogabob and fosfomycinStudies on organophosphorus compounds. Part 128. For Part 127, see C. Yuan, C. Xu and Y. Zhang, Tetrahedron, 2003, 59, 6095.
作者:Ke Wang、Yonghui Zhang、Chengye Yuan
DOI:10.1039/b307638p
日期:——
Phosphocarnitine was conveniently obtained from easily available diethyl 3-chloro-2-oxopropanephosphonates, followed by subsequent reduction, Mucor miehei lipase (IM) mediated resolution, amination and dealkylation. Candida antarctica lipase B (CALB) served as an effective biocatalyst in the resolution of several 1- or 2- hydroxyalkanephosphonates. The chlorine atom in different positions on the molecules greatly affected their enantioselectivity. CALB also showed satisfactory enantioselectivity toward those molecules bearing an azido moiety. Both enantiomers of phosphogabob and fosfomycin were also prepared via CALB-mediated resolution as the key step.
Nonenzymatic kinetic resolution of racemic α-hydroxyalkanephosphonates with chiral copper catalyst
作者:Yosuke Demizu、Atsushi Moriyama、Osamu Onomura
DOI:10.1016/j.tetlet.2009.07.003
日期:2009.9
Kinetic resolution of alpha-hydroxyalkanephosphonates was efficiently performed by benzoylation in the presence of copper(II) triflate and (R,R)-Ph-BOX as a catalyst with excellent s value of up to 286. (C) 2009 Elsevier Ltd. All rights reserved.
US6583182B1
申请人:——
公开号:US6583182B1
公开(公告)日:2003-06-24
Synthesis of Dialkyl Epoxyethylphosphonates
作者:Toshio AGAWA、Toshihiko KUBO、Yoshiki OHSHIRO
DOI:10.1055/s-1971-21664
日期:——
The first enantioselective [3+2] cycloaddition of epoxides to arylisocyanates: asymmetric synthesis of chiral oxazolidinone phosphonates
作者:Maria Teresa Barros、Ana Maria Faísca Phillips
DOI:10.1016/j.tetasy.2010.10.028
日期:2010.11
A [3+2] cycloaddition of diethyl 1 2-oxiranephosphonate to aryl isocyanates catalyzed by lanthanide cations is described The reaction is highly regioselective and 5-substituted 2-oxazolidinone phosphonates are obtained with a regioselectivity greater than 95 5 with respect to the 4-substituted regioisomer and in up to 84% yield When 20 mol % of Pybox-Yb3+ is used as a catalyst enantiomerically enriched products are obtained in up to 75% ee depending on the reaction conditions and the nature of the isocyanate Low temperatures benefit asymmetric induction but have an adverse effect on the regioselectivity for para-substituted aryl isocyanates (C) 2010 Elsevier Ltd All rights reserved