An aza-Payne rearrangement-epoxide ring opening reaction of 2-aziridinemethanols in a one-pot manner: A regio- and stereoselective synthetic route to diastereomerically pure N-protected 1,2-amino alcohols
A regio- and stereoselectivesyntheticroute to diastereomericallypure1,2-aminoalcohols via a one-potaza-Payne rearrangement - epoxide ringopeningreaction of 2-aziridinemethanols is reported.
A one-pot aza-Payne rearrangement-epoxide ring opening reaction of 2-aziridinemethanols: A regio- and stereoselective synthetic route to diastereomerically pure 1,2-amino alcohols
A regio- and stereoselectivesyntheticroute to diastereomericallypure1,2-aminoalcohols via a one-potaza-Payne rearrangement — epoxide ringopeningreaction of 2-aziridinemethanols is reported. Satisfactory yields are obtained in excellent diastereoisomeric excesses by successive exposure of 2-aziridinemethanols to potassium hydride and nucleophilic reagents in a one-potmanner.
An efficient kineticresolution of racemic trans-2,3-aziridinyl alcohols is established via zinc catalyzed ring opening reactions with various amines as the nucleophiles. The directing effect of the hydroxyl group and the precise enantiodiscrimination by dinuclear zinc cooperative catalyst are the keys to success of high regioselectivity and enantioselectivity. A range of enantioenriched vicinal diamines
通过以各种胺作为亲核试剂的锌催化开环反应,建立了外消旋反式-2,3-氮丙啶醇的有效动力学拆分。羟基的导向作用和双核锌协同催化剂的精确对映区分是高区域选择性和对映选择性成功的关键。一系列对映体富集的邻位二胺和反式-2,3-氮丙啶醇以良好的产率和优异的 ee 值获得。据我们所知,这是 2,3-氮丙啶醇的定向对映选择性亲核开环反应的第一个例子。
Aza-Payne Rearrangement of Activated 2-Aziridinemethanols and 2,3-Epoxy Amines under Basic Conditions
An aza-Payne rearrangement of activated 2-aziridinemethanols with t-BuOK, NaH, or KH at near 0 degrees C in common solvents such as THF, toluene, 1,2-dimethoxyethane, 1,4-dioxane, or a mixed solvent of THF-HMPA followed by quenching at -78 degrees C gives the corresponding epoxysulfonamides. Exposure of N-tosyl-(2S)-azetidinemethanol (36) and N-tosyl-(S)-prolinol (37) to NaH or KH in dichloromethane yielded only the respective dimeric compounds that resulted by joining 2 equiv of reactant through a methylene group. Reaction of N-tosyl-(2S,3S)-3-methyl-2-aziridinemethanol (9) and its (2R,3S)-isomer 23 with Gilman reagents (R(2)CuLi; R = Me and Bu) or ''higher order'' cuprates [R(2)Cu(CN)Li-2; R = Me and Bu] yielded the two expected aziridine ring-opening products. In sharp contrast, treatment of 9 and 23 with ''lower order'' cuprates afforded rearrangement-opened products. Thus, if the nucleophile is highly reactive, then the expected nucleophilic ring opening of the aziridine predominates. However, if the nucleophile is less reactive, then it becomes possible to cleave the resulting rearranged epoxide. Upon exposure of 2,3-epoxy amines to an equimolar mixture of t-BuOK-n-BuLi in a mixed solvent of THF and n-hexane at -78 degrees C, the equilibrium lies exclusively toward the hydroxy aziridine forming direction.