Gold-Catalyzed Cyclizations: A Comparative Study of ortho,ortho′-Substituted KITPHOS Monophosphines with their Biaryl Monophosphine Counterpart SPHOS
作者:A. Stephen K. Hashmi、Annette Loos、Simon Doherty、Julian G. Knight、Katharine J. Robson、Frank Rominger
DOI:10.1002/adsc.201000879
日期:2011.3.28
complexes of electron‐rich ortho,ortho′‐disubstituted KITPHOS (11‐dicyclohexylphosphino‐12‐phenyl‐9,10‐ethenoanthracene) monophosphines are efficient catalysts for intramolecular cycloisomerizations that afford phenols, 3‐acylindenes and methylene‐oxazolines; comparative catalyst testing showed that these catalysts either competed with or outperformed that based on SPHOS [2‐(2′,6′‐dimethoxybipheny
富电子的邻,邻二取代的KITPHOS(11-二环己基膦基-12-苯基-9,10-乙炔基蒽)单膦的亲电子三氟甲酰亚胺(三氟甲烷磺酰亚胺)配合物是分子内环异构化的有效催化剂,可提供酚类,3-酰基和亚甲基恶唑啉; 对比催化剂测试表明,这些催化剂与SPHOS [2-(2',6'-二甲氧基联苯)二环己基膦]相比具有竞争优势或优于后者。含单个邻位的富电子联芳基单膦铑催化的1-炔基(二环己基膦)氧化物与1,7-辛二炔之间的[2 + 2 + 2]环加成反应制得的-甲氧基取代基也形成了高效的相同转化催化剂。监测包含配位四氢噻吩的KITPHOS基三氟化金(I)配合物与仅由三氟阴离子阴离子配位的对应物之间的对比催化剂测试,发现前者的效率比后者低一个数量级,证实四氢噻吩可以是一种有效的催化剂抑制剂。