Asymmetric synthesis of cyclic β-amino acids and cyclic amines via sequential diastereoselective conjugate addition and ring closing metathesis
作者:Ann M Chippindale、Stephen G Davies、Keiji Iwamoto、Richard M Parkin、Christian A.P Smethurst、Andrew D Smith、Humberto Rodriguez-Solla
DOI:10.1016/s0040-4020(03)00411-3
日期:2003.4
β-unsaturated esters followed by ringclosingmetathesis is used to afford efficiently a range of substituted cyclic β-amino esters in high d.e. Alternatively, conjugate addition to α,β-unsaturated Weinreb amides, functional group conversion and ringclosingmetathesis affords cyclic amines in high d.e. The further application of this methodology to the synthesis of a range of carbocyclic β-amino esters via
Asymmetric synthesis and applications of β-amino Weinreb amides: asymmetric synthesis of (S)-coniine
作者:Anthony J. Burke、Stephen G. Davies、A. Christopher Garner、Tom D. McCarthy、Paul M. Roberts、Andrew D. Smith、Humberto Rodriguez-Solla、Richard J. Vickers
DOI:10.1039/b402531h
日期:——
Conjugate addition of lithium (S)-N-benzyl-N-alpha-methylbenzylamide to a range of alpha, beta-unsaturated Weinreb amides proceeds with high levels of diastereoselectivity (>95% de). The beta-amino Weinreb amide products may be transformed into beta-amino ketones via reactions with Grignard reagents, while treatment with DIBAL-H furnishes beta-amino aldehydes. Trapping of the aldehyde via Wadsworth-Emmons
Palladium-Catalyzed Preparation of Weinreb Amides from Boronic Acids and <i>N</i>-Methyl-<i>N</i>-methoxycarbamoyl Chloride
作者:Ravi Krishnamoorthy、Sang Q. Lam、Christopher M. Manley、R. Jason Herr
DOI:10.1021/jo902647h
日期:2010.2.19
A simple protocol for the synthesis of Weinreb benzamides and α,β-unsaturated Weinrebamides through a palladium-catalyzed cross-coupling reaction between organoboronic acids and N-methoxy-N-methylcarbamoyl chloride has been developed. The method is also applicable to the use of potassium organotrifluoroborates.
New Reagent for Convenient Access to the α,β-UnsaturatedN-Methoxy-N-methyl-amide Functionality by a Synthesis Based on the Julia Olefination Protocol
作者:Beedimane Narayana Manjunath、Neeraj P. Sane、Indrapal Singh Aidhen
DOI:10.1002/ejoc.200600126
日期:2006.6
A newreagent for the synthesis of the α,β-unsaturated N-methoxy-N-methyl-amide structural unit has been developed. 2-(Benzo[d]thiazol-2-ylsulfonyl)-N-methoxy-N-methylacetamide, a crystalline solid with an indefinite shelf life that can be easily prepared in two convenient steps from 2-chloro-N-methoxy-N-methylacetamide, reacted with a variety of aldehydes under Julia conditions to furnish the α,β-unsaturated