title: General Route to Cyclobutadiene Rhodium Complexes.
abstract: Cyclobutadiene rhodium complexes bear high potential for applications in organometallic synthesis and catalysis. We have found that the cyclobutadiene complexes with substitutionally labile p-xylene ligands [(C4 R4 )Rh(p-xylene)](+) can be synthesized in one step from the commercially available bis(ethylene) complex [{(C2 H4 )2 RhCl}2 ], p-xylene, and internal alkynes. The replacement of p-xylene by various ligands provides a general access to other [(C4 R4 )Rh] compounds, such as [(C4 R4 )RhCl]x , [(C4 R4 )RhL3 ](+) , [(C4 R4 )Rh(C5 H5 )], and [(C4 R4 )Rh(arene)](+) . Complex [(C4 Et4 )Rh(p-xylene)](+) also catalyzes an unusual cycloisomerization of a 1,11-dien-6-yne into a bicyclic diene.
authors.affiliation: Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilova str., 119991, Moscow (Russia).
authors.forename: Dmitry S
authors.initials: DS
authors.lastname: Perekalin
authors.affiliation: Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilova str., 119991, Moscow (Russia).
authors.forename: Nikita V
authors.initials: NV
authors.lastname: Shvydkiy
authors.affiliation: Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilova str., 119991, Moscow (Russia).
authors.forename: Yulia V
authors.initials: YV
authors.lastname: Nelyubina
authors.affiliation: Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilova str., 119991, Moscow (Russia). arkudinov@ineos.ac.ru.
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Kudinov
keywords: cyclobutadienes; diene ligands; homogeneous catalysis; rhodium; sandwich complexes