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 -N
UPHOS)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-N
UPHOS)。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 -N
UPHOS)。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