Diastereoselective Synthesis of β-Heteroaryl syn-α-Methyl-β-Amino Acid Derivatives via a Double Chiral Auxiliary Approach
摘要:
The addition of the SuperQuat enolate to five- and six-membered heterocyclic tert-butyl sulfinimines led to a high syn-selectivity of up to 99:1 in good to excellent yields. The reaction Is tentatively proposed to proceed through an open-chain transition state with the presence of an alpha-heteroatom on the sulfinimine leading to high diastereoselectivities. The adducts were derivatized to beta-amino esters and amides in a facile manner.
Asymmetric Synthesis of α,α-Difluoro-β-amino Acid Derivatives from Enantiomerically Pure <i>N-tert-</i>Butylsulfinimines
作者:Donnette D. Staas、Kelly L. Savage、Carl F. Homnick、Nancy N. Tsou、Richard G. Ball
DOI:10.1021/jo0259313
日期:2002.11.1
reagent derived from ethyl bromodifluoroacetate to alkyl- and aryl-substituted N-tert-butylsulfinimines furnishes beta-tert-butylsulfinamyl-beta-substituted alpha,alpha-difluoroproponiates in diastereomeric ratios ranging from 80:20 to 95:5. The diastereomers are easily separated and the enantiomerically pure, protected beta-amino esters are readily transformed to the corresponding acid, amide, and amine
Diastereoselective Synthesis of β-Heteroaryl <i>syn</i>-α-Methyl-β-Amino Acid Derivatives via a Double Chiral Auxiliary Approach
作者:Jianwei Bian、David Blakemore、Joseph S. Warmus、Jianmin Sun、Matthew Corbett、Colin R. Rose、Bruce M. Bechle
DOI:10.1021/ol3033785
日期:2013.2.1
The addition of the SuperQuat enolate to five- and six-membered heterocyclic tert-butyl sulfinimines led to a high syn-selectivity of up to 99:1 in good to excellent yields. The reaction Is tentatively proposed to proceed through an open-chain transition state with the presence of an alpha-heteroatom on the sulfinimine leading to high diastereoselectivities. The adducts were derivatized to beta-amino esters and amides in a facile manner.