Reductive elimination of halogens assisted by phosphine ligands in Fe(CO)4X2 (X = I, Br) complexes

被引:24
作者
Bellachioma, Gianfranco [1 ]
Cardaci, Giuseppe [1 ]
Macchioni, Alceo [1 ]
Venturi, Chiara [1 ]
Zuccaccia, Cristiano [1 ]
机构
[1] Univ Perugia, Dipartimento Chim, I-06123 Perugia, Italy
关键词
reductive elimination; carbonyl halide iron complexes; phosphonium salts; radical mechanism;
D O I
10.1016/j.jorganchem.2006.05.041
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
Fe(CO)(4)X-2 complexes [X = I (1), Br(1')] react with phosphine ligands L (L = PMe3, PEt3, PMe2Ph, PMePh2, PPh3) via a two-step mechanism: in the first step fac-Fe(CO)(3)LX2 Complexes are formed; in the second step two parallel pathways, a and b, are observed; in pathway a, reductive elimination with formation of equimolar amounts of Fe(CO)(3)L-2 (5) and phosphonium salts [LX]X-+(-) is observed; in pathway b, disubstituted dihalide complexes cis,trans,cis-Fe(CO)(2)L2X2 are formed. The relative weights of pathways a and b depend on the basicity, steric hindrance and concentration of ligand L, on the nature of the halogen and on temperature. A radical mechanism which accounts for most of the experimental results is proposed. (c) 2006 Elsevier B.V. All rights reserved.
引用
收藏
页码:3881 / 3888
页数:8
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