Facile synthesis of both enantiomers of (pyrrolidin-2-yl)phosphonate from l-proline
作者:Shigeo Hirata、Masami Kuriyama、Osamu Onomura
DOI:10.1016/j.tet.2011.09.080
日期:2011.12
Diastereoselective introduction of phosphono groups into L-proline derivatives at the 5-position was achieved with suitable selection of N-protecting group. N-Benzoyl-L-prolinate preferentially gave trans-phosphorylated products, which could be easily transformed into (S)-(pyrrolidin-2-yl)phosphonates. On the other hand, N-benzyloxycarbonyl-L-prolinate reacted with phosphite to give cis-substituted products, which could be easily transformed into (R)-(pyrrolidin-2-yl)phosphonates. (C) 2011 Elsevier Ltd. All rights reserved.
Aminophosphonates as organocatalysts in the direct asymmetric aldol reaction: towards syn selectivity in the presence of Lewis bases
作者:Peter Dinér、Mohamed Amedjkouh
DOI:10.1039/b605091c
日期:——
and their performance was evaluated as organocatalysts in the direct asymmetric aldol reaction. High enantioselectivities (up to 99% ee) were achieved for a range of substituted cyclohexanones and benzaldehydes. Several organic bases, such as DBU, DBN, and TMG, were used together with the alpha-aminophosphonates in the aldol reactions and were found to favor syn-selectivity.
Asymmetric Synthesis of Enantiomerically Pure Phosphonic Analogues of Glutamic Acid and Proline
作者:Ulrich Groth、Lutz Richter、Ulrich Schöllkopf
DOI:10.1016/s0040-4020(01)80584-6
日期:1992.1
Michael addition of the metallated camphor derivatives 2 to vinylogous esters and subsequential hydrolysis afforded phosphonic analogues of glutamic acid. The enantiomericallypure lactam 6 was reduced by LiBH4/BF3·OEt2 to phosphoproline 7.