Phase-transfer-catalysed asymmetric synthesis of tetrasubstituted allenes
作者:Takuya Hashimoto、Kazuki Sakata、Fumiko Tamakuni、Mark J. Dutton、Keiji Maruoka
DOI:10.1038/nchem.1567
日期:2013.3
Allenes are molecules based on three carbons connected by two cumulated carbon–carbon double bonds. Given their axially chiral nature and unique reactivity, substituted allenes have a variety of applications in organic chemistry as key synthetic intermediates and directly as part of biologically active compounds. Although the demands for these motivated many endeavours to make axially chiral, substituted
Diethyl Phosphite Initiated Coupling of α-Ketoesters with Imines for Synthesis of α-Phosphonyloxy-β-amino Acid Derivatives and Aziridine-2-carboxylates
作者:Jin Jiang、Hui Liu、Chong-Dao Lu、Yan-Jun Xu
DOI:10.1021/acs.orglett.6b00273
日期:2016.2.19
Coupling of α-ketoesters with imines initiated by diethylphosphite in the presence of alkaline metal hexamethyldisilazides is reported. Base-promoted addition of diethylphosphite to α-ketoesters, followed by [1,2]-phosphonate/phosphate rearrangement, generates α-phosphonyloxy enolates that are subsequently intercepted by imines. The use of suitable azomethine coupling partners allows selective construction
Asymmetric organocatalytic decarboxylative Mannich reaction using β-keto acids: A new protocol for the synthesis of chiral β-amino ketones
作者:Chunhui Jiang、Fangrui Zhong、Yixin Lu
DOI:10.3762/bjoc.8.144
日期:——
The first decarboxylativeMannichreaction employing beta-keto acids, catalyzed by cinchonine-derived bifunctional thiourea catalyst has been described. The desired beta-amino ketones were obtained in excellent yields and with moderate to good enantioselectivities.