Short Synthesis of Chiral 4-Substituted (S)-Imidazolinium Salts Bearing Sulfonates and Their Use in γ-Selective Reactions of Allylic Halides with Grignard Reagents
作者:Christopher M. Latham、Alexander J. Blake、William Lewis、Matthew Lawrence、Simon Woodward
DOI:10.1002/ejoc.201101336
日期:2012.2
A one-pot reaction of Boc-protected amino alcohols and 2-sulfobenzoic anhydride followed by the addition of a wide variety of primary amines has allowed rapid access to diverse libraries of amidosulfonates 1,2-C6H4(SO3–)(COCHR1CH2NH2+R2) (R1 = Bn, iPr, Ph; R2 = aryl, CHMePh, 1-adamantyl), of which two examples have been characterised by X-ray crystallography. These reactions proceed by SN2 opening
Boc 保护的氨基醇和 2-磺基苯甲酸酐的一锅反应,然后加入各种伯胺,可以快速访问不同的氨基磺酸盐库 1,2-C6H4(SO3–)(COCHR1CH2NH2+R2) (R1 = Bn、iPr、Ph;R2 = 芳基、CHMePh、1-金刚烷基),其中两个例子已通过 X 射线晶体学表征。这些反应通过未分离的恶唑啉中间体的 SN2 打开进行。氨基磺酸盐已在两步过程中转化为咪唑啉磺酸盐两性离子(N-杂环卡宾前体),包括用 BH3·SMe2 还原和用 HC(OEt)3 环化。两个例子(R1 = Bn,R2 = 2,6-iPrC6H3 和 R1 = iPr,R2 = 3,5-Me2C6H3)已被结晶学表征,后者为 PF6 盐。咪唑啉磺酸盐两性离子 (1 mol-%) 催化 RMgBr (R = 烷基) 添加到 (E)-ArC(R) = CHCH2Br (R = H, Me)。添加到肉桂基溴化物中显示出高