Synthesis of a New Class of 1,4-Bis(diphenylphosphino)-1,3-butadiene Bridged Diphosphine, NUPHOS, via Zirconium-Mediated Reductive Coupling of Alkynes and Diynes: Applications in Palladium-Catalyzed Cross-Coupling Reactions
作者:Simon Doherty、Edward G. Robins、Mark Nieuwenhuyzen、Julian G. Knight、Paul A. Champkin、William Clegg
DOI:10.1021/om011049w
日期:2002.4.1
cross-coupling of bromobenzene and sec-butylmagnesium bromide. Catalyst mixtures based on 1,2,3,4-Ph4-NUPHOS are far superior to those based on BINAP, with activities of 6900 and 260 (mol of product) (mol of palladium)-1 h-1, respectively. In fact, catalysts based on 1,2,3,4-Ph4-NUPHOS are ∼30 times more active than the most active catalyst reported to date for this coupling. In comparison, the selectivity of
锆介导的炔烃和二炔的分子间和分子内还原环化已被用于制备基于四碳sp 2杂化的系链的新型双齿膦。用Negishi's试剂将二苯乙炔和but-2-yne进行分子间偶联,然后用氯化铜进行金属转移,然后用氯二苯膦淬灭,得到相应的无环二膦1,4-双(二苯基膦基)-1,2,3,4-四苯基-1, 3-丁二烯(2a ; 1,2,3,4-Ph 4 -NUPHOS)和1,4-双(二苯基膦基)-1,2,3,4-四甲基-1,3-丁二烯(2b ; 1,2 ,3,4-Me 4-NUPHOS)。已经获得了前者的单晶X射线分析。出人意料的是,1-苯基丙炔进行了高度区域选择性的还原环化反应,得到1,4-双(二苯基膦基)-1,3-二苯基-2,4-二甲基-1,3-丁二烯(2c ; 1,3-Ph 2 -2 ,4-Me 2 -NUPHOS)。类似地,由3,9-十二碳二烯和1,8-二苯基辛二炔产生的氧化锆环戊二烯的金属转移,然后用氯