α,β-functionalization of enones via pentacovalent oxaphospholenes
摘要:
2,2,2-Triethoxy-1,2-lambda-5-oxaphospholene, 1, reacts under mild, neutral conditions with bromine, dialkyl azodicarboxylates, and oxaziridines to produce beta-heteroatom substituted gamma-ketophosphonates and beta-acyl vinyl phosphonate in high yields.
Synthesis of Phosphonomethyl Tetrahydrofurans via the Mori–Tamaru Reaction of Phosphonodienes
作者:Rishi R. Paudel、Jeremy N. Ridenour、Nigam P. Rath、Christopher D. Spilling
DOI:10.1021/acs.orglett.0c01080
日期:2020.5.15
(the Mori-Tamaru reaction) gives hydroxy vinyl phosphonates in good yields with excellent control of the relative stereochemistry. Base-induced cyclization of the vinyl phosphonates yields phosphonomethyl-substituted tetrahydrofurans. Inversion of the hydroxyl stereochemistry by Mitsunobu reaction and then cyclization yields a different set of phosphonomethyl-substituted tetrahydrofuran diastereoisomers
Asymmetric synthesis of β- and γ-amidophosphonates by Diels–Alder reaction using chiral aminodiene: theoretical and experimental study of the facial selectivity of chiral N-dienyl lactam
作者:Raphaël Robiette、Jacqueline Marchand-Brynaert
DOI:10.1039/b105070m
日期:——
Asymmetric [4 + 2] cycloaddition of optically pure 1-aminodiene 1 onto substituted phosphonodienophiles 2 and 4 provided respectively chiral β- and γ-amidophosphonocyclohexenes with good selectivities. The absolute stereochemistry of the major diastereoisomer was experimentally proved by NMR experiments and the facial selectivity of diene 1 is discussed on the basis of ab initio calculations.
efficiency of the oxazolidin-2-thione chiral auxiliary in the facial discrimination of Diels-Alder reactions. The absolute configuration of the 3,4,5-trisubstituted cyclohexene derivatives (3a-c) was established by X-ray diffraction analysis. NMR studies confirmed the relative stereochemistries and showed two possible conformers in solution. (C) 2007 Elsevier B.V. All rights reserved.
Diels-Alder reactivity of a ketovinylphosphonate with cyclopentadiene and furan
作者:Cynthia K. McClure、Karl B. Hansen
DOI:10.1016/0040-4039(96)00235-3
日期:1996.3
The Diels-Alder reactions between diethyl ketovinylphosphonate 5 and cyclopentadiene or furan were performed with and without Lewis acid assistance. The acetyl group directed endo in all cases, with ratios varying from 1.4:1 –6.7:1 (acetyl endo).
Diels-Alder Reactivity of a Keto Vinylphosphonate. Empirical and Theoretical Observations. Application to the Syntheses of Phosphonate Analogues of Myo-Inositol
作者:Cynthia McClure、Karl Hansen、Keith Herzog、Jeffrey Link、Frederick Arnold
DOI:10.1080/10426509608046266
日期:1996.2.1
Abstract The Diels-Alderreactivity of the keto vinylphosphonate 1 with furan, cyclopentadiene and E-1-acetoxy-1,3-butadiene was investigated with and without Lewis acid assistance. The acetyl group directed in each case. LUMO molecular orbital coefficients were obtained via ab initio (3-21G*) calculations, and support the experimental data. The Diels-Alder products from the reactions with furan and 1-acetoxybutadiene
摘要 研究了有和没有路易斯酸辅助下酮基乙烯基膦酸酯 1 与呋喃、环戊二烯和 E-1-乙酰氧基-1,3-丁二烯的 Diels-Alder 反应性。在每种情况下都指向乙酰基。LUMO 分子轨道系数是通过 ab initio (3-21G*) 计算获得的,并支持实验数据。来自与呋喃和 1-乙酰氧基丁二烯反应的 Diels-Alder 产物被用于肌醇的膦酸酯类似物。