Stereoselective synthesis and Lewis acid mediated functionalization of novel 3-methylthio-β-lactams
作者:Shamsher S. Bari、Reshma、Aman Bhalla、Geeta Hundal
DOI:10.1016/j.tet.2009.09.086
日期:2009.11
subjected to Lewis acid (TiCl4 or SnCl4) mediated functionalization using various active aromatic, heterocyclic and aliphatic compounds (nucleophiles). This reaction provides an easy access to novel, stereoselective cis-3-monosubstituted-3-methylthio-β-lactams, which further undergo smooth desulfurization with Raney-nickel to afford C-3 cis- and trans-monosubstituted-β-lactams. The cis or trans configuration
描述了一种新颖的3-甲硫基-β-内酰胺的立体选择性合成及其路易斯酸介导的功能化的熟练礼节。在施陶丁格反应中对2-甲基硫代乙酸和适当的亚胺的处理导致了新型反式-3-甲硫基-β-内酰胺的立体控制合成,收率很高。使用N-氯代琥珀酰亚胺(NCS)和AIBN对反式-3-甲硫基-β-内酰胺进行立体选择性氯化制得的顺式-3-氯代3-甲硫基-β-内酰胺,经路易斯酸(TiCl 4或SnCl 4)介导的功能化,使用各种活性的芳香族,杂环和脂肪族化合物(亲核试剂)。该反应提供了容易获得新的立体选择性的顺式-3-单取代的3-甲硫基-β-内酰胺,其进一步用阮内镍进行平滑的脱硫以提供C-3的顺式和反式-单取代的β-内酰胺。相对于C4-H,分配了C-3处氢/氯/亲核基取代基的顺式或反式构型。