Diastereoselective Synthesis of 2-Amino-4-phosphonobutanoic Acids by Conjugate Addition of Lithiated Schöllkopf's Bislactim Ethers to Vinylphosphonates
作者:María Ruiz、M. Carmen Fernández、Aniana Díaz、José M. Quintela、Vicente Ojea
DOI:10.1021/jo034707q
日期:2003.10.1
Conjugateadditions of lithiatedbislactimethers derived from cyclo-[Gly-Val] and cyclo-[Ala-Val] to alpha-, beta-, or alpha,beta-substituted vinylphosphonates allow direct and stereoselective access to a variety of 3- or 4-monosubstituted and 2,3-, 2,4-, or 3,4-disubstituted 2-amino-4-phosphonobutanoic acids (AP4 derivatives) in enantiomerically pure form. The relative stereochemistry was assigned
A new version of the Peterson olefination using bis(trimethylsilyl)methyl derivatives and fluoride ion as catalyst
作者:Claudio Palomo、Jesus M. Aizpurua、Jesus M. Garcia、Inaki Ganboa、F. P. Cossio、Begona Lecea、Concepcion Lopez
DOI:10.1021/jo00295a047
日期:1990.4
Hydrophosphorylation of Terminal Alkynes Catalyzed by Palladium
作者:N. S. Gulykina、T. M. Dolgina、G. N. Bondarenko、I. P. Beletskaya
DOI:10.1023/b:rujo.0000003155.15312.f4
日期:2003.6
A series of new 1-aryl-, 1-heteroaryl-, and 1-alkylethenylphosphonates was prepared by hydrophosphorylation of terminal acetylenes catalyzed by palladium. A stable in air complex Pd-2(dba)(3) (.) CHCl3 was applied as catalyst. The reaction mechanism is discussed.
Diastereo- and enantioselective synthesis of 2,3- and 1,2-disubstituted 4-oxophosphonates via asymmetric Michael addition
Asymmetric Michael addition of lithiated SAMP hydrazones (S)-2 to a variety of alkenylphosphonates (E)-3 followed by oxidative cleavage of the 1,4-adducts 4 afforded 2,3-disubstituted 4-oxophosphonates 5 with good to very good yields (58-80%), low to moderate diastereomeric (de = 6-74%) and excellent enantiomeric excesses (ee = >93%). Pure anti-diastereomers (ee = >93%) of 5 were obtained by separation of the stereoisomers by HPLC. In addition, the lithiated SAMP hydrazone (S)-2a was added to alkenylphosphonates (E)-3, and the lithio phosphonate anions were trapped with alkyl halides or sulfates, yielding 1,2-disubstituted 4-oxophosphonates 8 with moderate to good yields (38-69%), low to good diastereomeric (de = 10-77%) and high enantiomeric excesses (ee = >90%) after oxidative cleavage. (C) 1997 Elsevier Science Ltd.
PALOMO, CLAUDIO;AIZPURUA, JESUS M.;GARCIA, JESUS M.;GANBOA, INAKI;COSSIO,+, J. ORG. CHEM., 55,(1990) N, C. 2498-2503
作者:PALOMO, CLAUDIO、AIZPURUA, JESUS M.、GARCIA, JESUS M.、GANBOA, INAKI、COSSIO,+