Conversion of .beta.-amino esters to .beta.-lactams via tin(II) amides
摘要:
Addition of Sn[N(TMS)2]2 to beta-amino esters with sterically nondemanding substituents at C3 or on nitrogen gave beta-lactams in 76-100% yield. More sterically demanding beta-amino esters could be converted to beta-lactams in excellent yield using unsymmetrical tin(II) amide reagents which were prepared in situ. Optimal results for the in situ procedure involved addition of Sn[N(TMS)2]2 to a beta-amino ester, followed by addition of either pivalic acid or N-tert-butylacetamide.
alkyl radical generation and cyclization to prepare substituted indolines in a green, metal-free procedure. This method complements the Fischer indolization, metal-catalyzed couplings, and photocatalyzed radical addition and cyclization. A wide range of functional groups is tolerated, including aryl halides, that would not be compatible with most existing methods. Electronic bias and substitution were