Chiral Thioureas Promote Enantioselective Pictet–Spengler Cyclization by Stabilizing Every Intermediate and Transition State in the Carboxylic Acid-Catalyzed Reaction
作者:Rebekka S. Klausen、C. Rose Kennedy、Alan M. Hyde、Eric N. Jacobsen
DOI:10.1021/jacs.7b06811
日期:2017.9.6
mechanism of benzoic acid/thiourea co-catalysis in the asymmetric Pictet–Spengler reaction is reported. Kinetic, computational, and structure–activity relationship studies provide evidence that rearomatization via deprotonation of the pentahydro-β-carbolinium ion intermediate by a chiralthiourea·carboxylate complex is both rate- and enantioselectivity-determining. The thiourea catalyst induces rate acceleration
A New Chiral Catalyst for the Enantioselective Strecker Synthesis of α-Amino Acids
作者:Jinkun Huang、E. J. Corey
DOI:10.1021/ol047698w
日期:2004.12.1
The chiral ammonium salt 3 is demonstrated to be an effective catalyst for the highly enantioselective Strecker reaction of N-allylbenzaldimines with hydrogen cyanide in CH2Cl2 solution.
Rhodium(I)-Catalysed Isomerisation of<i>N</i>-Allylimines to 2-Aza-1,3-dienes
作者:Ronald Grigg、Paul J. Stevenson
DOI:10.1055/s-1983-30603
日期:——
GRIGG, R.;STEVENSON, P. J., SYNTHESIS, BRD, 1983, N 12, 1009-1010
作者:GRIGG, R.、STEVENSON, P. J.
DOI:——
日期:——
Propylphosphonic anhydride (T3P) mediated synthesis of β-lactams from imines and aryl-substituted acetic acids
作者:Graeme Coulthard、William P. Unsworth、Richard J.K. Taylor
DOI:10.1016/j.tetlet.2015.01.009
日期:2015.6
β-Lactams were prepared from imines and aryl-substituted aceticacids using T3P as an activating agent. In most cases, good to excellent yields were obtained (up to 93%) and the trans-β-lactam was the exclusive or major diastereoisomer (confirmed through analysis of 1H NMR coupling constants and by X-ray crystallography).
使用T3P作为活化剂,由亚胺和芳基取代的乙酸制备β-内酰胺。在大多数情况下,可获得良好至优异的收率(高达93%),反式-β-内酰胺是唯一或主要的非对映异构体(通过1 H NMR偶合常数分析和X射线晶体学证实)。