Enantioselective trapping of phosphoramidate ammonium ylides with imino esters for synthesis of 2,3-diaminosuccinic acid derivatives
作者:Jun Jiang、Xiaochu Ma、Shunying Liu、Yu Qian、Fengping Lv、Lin Qiu、Xiang Wu、Wenhao Hu
DOI:10.1039/c3cc36972b
日期:——
A highly enantioselective trapping of protic phosphoramidate ammonium ylides with α-imino esters is reported. The intriguing Rh2(OAc)4 and chiral Brønsted acid co-catalyzed three-component Mannich-type reaction of a diazo compound, a phosphoramidate, and an α-imino ester provides a rapid and efficient access to 2,3-diaminosuccinic acid derivatives with a high level control of diastereo- and enantioselectivity.
Enantioselective Intermolecular Carbon-Carbon Bond Formation of Glyoxylate Imines with Allylstannanes Catalyzed by tropos BIPHEP-Gold(I) Complexes with Au-Au Interactions
作者:Masafumi Kojima、Koichi Mikami
DOI:10.1002/chem.201103023
日期:2011.12.9
Interactions act: The enantioselective allylation reaction of glyoxylateiminescatalyzed by tropos DM‐BIPHEP–gold(I) complexes with an Au–Auinteraction was developed to give a higher enantioselectivity than the atropos DM‐BINAP–gold complexes without an Au–Auinteraction (see scheme).
The cobalt-catalyzed aza-NHK (Nozaki–Hiyama–Kishi) reaction of ketimine has been realized to access diverse α-tertiary vinylic amino esters with excellent enantioselectivity and broad functional group tolerance. Notably, both configuration of alkenyl halide provides the same stereochemical outcome of chiral α-alkenyl quaternary amino ester, indicating that isomerization of alkenyl fragment might be
Direct Asymmetric <i>a</i><i>nti</i>-Mannich-Type Reactions Catalyzed by a Designed Amino Acid
作者:Susumu Mitsumori、Haile Zhang、Paul Ha-Yeon Cheong、K. N. Houk、Fujie Tanaka、Carlos F. Barbas
DOI:10.1021/ja056984f
日期:2006.2.1
The development of catalysts for Mannich-type reactions that afford anti-products with excellent diastereo- and enantioselectivities under mild conditions and low catalyst loadings (1-5 mol %) is reported. Based on principles gained from the study of (S)-proline-catalyzed Mannich-type reactions that afford enantiomerically enriched syn-products, (3R,5R)-5-methyl-3-pyrrolidinecarboxylic acid (RR35) has been designed to catalyze the direct enantioselective anti-selective Mannich-type reactions. Computational studies of the above reaction using HF/6-31G* level of theory suggested that this design would be highly effective. The catalyst was subsequently synthesized and studied in organocatalytic Mannich-type reactions between unmodified aldehydes and N-PMP-protected alpha-imino esters. In accord with the design principles and in quantitative agreement with the theoretical predictions, reactions catalyzed by this catalyst afforded anti-products in good yields with excellent diastereo- and enantioselectivities (anti:syn 94:6 to 98:2, >97 to >99% ee).