An unprecedented intramolecular coupling of o-carboranyl and cyclopentadienyl. Synthesis and structural characterization of a ruthenium complex containing a novel doubly-bridged cyclopentadienyl-carboranyl ligand

Yi Sun, Hoi-Shan Chan, Pierre H. Dixneuf, Zuowei Xie
2004 Chemical Communications  
A novel ruthenium-mediated coupling reaction of a carboranyl with a cyclopentadienyl was discovered for the first time, leading to a brand new doubly-bridged cyclopentadienylcarboranyl ligand bearing two five-membered rings and to a new type of chiral ruthenium complex. Carboranes are finding many applications in catalysis, 1 boron neutron capture therapy, 2 siloxane-linked polymers, 3 solvent extraction of radionuclides, 4 and ceramics. 5 Thus their functionalizations become an important
more » ... an important subject in this area of research. C,C'linked o-carboranes are usually prepared via (1) salt metathesis reactions of Li 2 C 2 B 10 H 10 with dihalides, 6 (2) fluoride ion promoted intramolecular cycloaddition of o-carboranes bearing carbonyl groups, 7 and (3) intermolecular cycloaddition of 1,2-dehydro-ocarborane with dienes. 8 We have recently developed a new class of linked cyclopentadienyl-carboranyl compounds that are widely used as versatile ligands in organometallic chemistry, 9 and would like to extend this singly-bridged system to a doubly-bridged one as a convenient way to introduce a planar chirality into g 5cyclopentadienyl metal complexes. It is found, however, that the above three commonly used methods are not applicable to the doubly-bridged cyclopentadienyl-carboranyl system. We then 2 5 8 8 C h e m . C o m m u n . , 2 0 0 4 , 2 5 8 8 -2 5 8 9 T h i s j o u r n a l i s ß T h e R o y a l S o c i e t y o f C h e m i s t r y 2 0 0 4
doi:10.1039/b409772f pmid:15543293 fatcat:ld7dxyb6cvecjo5vqjdc7i7keq