An enantioselective synthesis of the carzinophilin degradation product (2s,3s) 4-amino-2,3-dihydroxy-3-methylbutyric acid
作者:Philip Garner、Jung Min Park、Vincent Rotello
DOI:10.1016/s0040-4039(00)98282-0
日期:1985.1
An efficient, enantioselective synthesis of (2S,3S) 4-amino-2,3-dihydroxy-3-methylbutyric acid (1) is described. The sequence includes the direct use of azide to selectively open a secondary epoxy alcohol formed under Payne rearrangement conditions.
Synthesis of N-heterocycles, beta-amino acids, and allyl amines via aza-payne mediated reaction of ylides and hydroxy aziridines
申请人:Borhan Babak
公开号:US20090012120A1
公开(公告)日:2009-01-08
An ylide-based aza-Payne rearrangement of 2,3-aziridin-
1
-ols leads to an efficient process for the preparation of pyrrolidines. The aza-Payne rearrangement under the basic reaction conditions favors the formation of epoxy amines. Subsequent nucleophilic attack of the epoxide by the ylide yields a bis-anion, which upon a 5-exo-tet ring closure yields the desired pyrrolidine, thus completing the relay of the 3-membered the 5-membered nitrogen containing ring system. This process takes place with complete transfer of stereochemical fidelity, and can be applied to sterically hindered aziridinols.
Synthesis of Chiral Tertiary Boronic Esters by Oxime-Directed Catalytic Asymmetric Hydroboration
作者:Veronika M. Shoba、Nathan C. Thacker、Andrew J. Bochat、James M. Takacs
DOI:10.1002/anie.201509137
日期:2016.1.22
now report that the oxime‐directed CAHB of alkyl‐substituted methylidene and trisubstituted alkene substrates by pinacolborane (pinBH) affords oxime‐containing chiral tertiary boronic esters with yields up to 87 % and enantiomeric ratios up to 96:4 e.r. The utility of the method is demonstrated by the formation of chiral diols and O‐substitutedhydroxylamines, the generation of quaternary carbon stereocenters
Selectivity in the Addition Reactions of Organometallic Reagents to Aziridine-2-carboxaldehydes: The Effects of Protecting Groups and Substitution Patterns
作者:Aman Kulshrestha、Jennifer M. Schomaker、Daniel Holmes、Richard J. Staples、James E. Jackson、Babak Borhan
DOI:10.1002/chem.201101168
日期:2011.10.24
especially the electronic character and conformational preferences of the nitrogen protectinggroups. To help rationalize the observed stereochemical outcomes, conformational and electronic structural analyses of a series of modelsystems representing the various substitution patterns have been explored by density functional calculations at the B3LYP/6‐31G* level of theory with the SM8 solvation model to account