Negishi cross-coupling reaction catalyzed by an aliphatic, phosphine based pincer complex of palladium. biaryl formation via cationic pincer-type PdIV intermediates
作者:Roman Gerber、Olivier Blacque、Christian M. Frech
DOI:10.1039/c1dt10398a
日期:——
The aliphatic, phosphine-based pincer complex [(C10H13-1,3-(CH2P(Cy2)2)Pd(Cl)] (1) is a highly active Negishi catalyst, enable to quantitatively couple various electronically activated, non-activated, deactivated, sterically hindered and functionalized aryl bromides with various diarylzinc reagents within short reaction times and low catalyst loadings. Experimental observations strongly indicate that
脂族,基于膦的钳形配合物[(C 10 H 13 -1,3-(CH 2 P(Cy 2)2)Pd(Cl)]](1)是一种高活性Negishi催化剂,能够定量偶联各种电子在短反应时间和低催化剂负载下,用各种二芳基锌试剂活化,未活化,失活,位阻和官能化的芳基溴化物的实验结果强烈表明,分子机理在初始氯离解为1并形成阳离子T-时是有效的成形14E -配合物[(C 10 H ^ 13 -1,3-(CH 2 P(C6 H 11) 2) 2)Pd] +( B),然后对其进行氧化加成芳基溴(Ar'Br),得到阳离子型五配位芳基溴钳形配合物[(C 10 H 13 -1) ,3-(CH 2 P(Cy 2) 2)Pd(Br)(芳基')] +( C),金属中心处于+ IV氧化态,芳基单元相对于脂肪族钳形核处于顺式位置。随后用Zn(芳基) 2进行金属转移,生成了[[C 10 H13 -1,3-(CH 2 P(Cy 2)