Pd-Catalyzed Directed <i>ortho</i>-C–H Alkenylation of Phenylalanine Derivatives
作者:Alfonso García-Rubia、Eduardo Laga、Carlos Cativiela、Esteban P. Urriolabeitia、Ramón Gómez-Arrayás、Juan C. Carretero
DOI:10.1021/jo502912m
日期:2015.3.20
A practical Pd-catalyzed ortho-olefination of enantioenriched N-(SO2Py)-protected aryl-alanine and norephedrine derivatives with electron-deficient alkenes has been developed using N-fluoro-2,4,6-trimethylpyridinium triflate as the terminal oxidant. The reaction occurs efficiently with excellent monosubstitution selectivity and without loss of enantiopurity. This cross-coupling proved to be broad in scope, tolerating a variety of steric and electronic changes to both coupling partners. Removal of the directing group under mild conditions provides access to optically active tetrahydroisoquinoline-3-carboxylic acid derivatives (Tics) with good diastereocontrol and with very small erosion of enantiomeric purity.
DIRECT STEREOSPECIFIC SYNTHESIS OF UNPROTECTED AZIRIDINES FROM OLEFINS
申请人:ESS Daniel Halsell
公开号:US20160340305A1
公开(公告)日:2016-11-24
A method for the direct stereospecific conversion of structurally diverse mono-, di-, tri- and tetra-substituted olefins to N—H, N-alkyl, N-cycloalkyl, or N-aralkyl aziridines using a hydroxylamine amination agent with transition metal catalyst. The method is operationally simple (i.e., one-pot), scalable and fast at ambient temperature.