Photogenerated Quinone Methides as Useful Intermediates in the Synthesis of Chiral BINOL Ligands
作者:Stefano Colloredo-Mels、Filippo Doria、Daniela Verga、Mauro Freccero
DOI:10.1021/jo060227y
日期:2006.5.1
The photoinduced synthesis of chiral 3,3‘-CH2X-disubstituted BINOL ligands (X = NR2, SR, OH) has been achieved with excellent ee by UV−visible activation of BINOLAMs bearing l-proline ester arms. Quinone methides, detected by laser flash photolysis, are the key intermediates involved in such a synthetic protocol, which undergo reversible nucleophilic conjugate additions by a great variety of nitrogen
手性3,3'- CH的光致合成2 X二取代BINOL配体(X = NR 2,SR,OH)已经通过BINOLAMs轴承的UV-可见光活化优异的ee值达到升-脯氨酸酯臂。通过激光闪光光解法检测到的醌甲基化物是此类合成方案中涉及的关键中间体,它们通过多种氮亲核试剂(胺和α-氨基酸衍生物)经历可逆的亲核偶联物加成,并完全保留了BINOL部分的构型。