title: Rearrangements and stereomutations of metallacycles derived from allenes and imidozirconium complexes.
abstract: The mechanisms of the rearrangements and stereoinversion of azametallacyclobutenes generated via [2+2] cycloaddition of allenes and imidozirconium complexes have been studied. Metallacycles derived from allenes bearing beta-hydrogen atoms racemize at room temperature by reversible beta-hydride elimination, a process which is also responsible for their eventual conversion to monoazadiene complexes. Metallacycles derived from diarylallenes racemize by reversible thermal bond homolysis at 95 degrees C; racemization of these metallacycles is also catalyzed by mild oxidants.
authors.affiliation: Department of Chemistry, University of California, Berkeley, CA 94720, USA.
authors.forename: Forrest E
authors.initials: FE
authors.lastname: Michael
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Duncan
authors.forename: Zachary K
authors.initials: ZK
authors.lastname: Sweeney
authors.forename: Robert G
authors.initials: RG
authors.lastname: Bergman
mesh_terms: D000466:Alkadienes / Q000737:chemistry*; D002384:Catalysis; D002942:Circular Dichroism; D018360:Crystallography, X-Ray; D003500:Cyclization; D003503:Cyclobutanes / Q000138:chemical synthesis* / Q000737:chemistry; D007700:Kinetics; D009942:Organometallic Compounds / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism; D013816:Thermodynamics; D015040:Zirconium / Q000737:chemistry*
chemical_list: D000466:Alkadienes; D003503:Cyclobutanes; D009942:Organometallic Compounds; C025947:propadiene; D015040:Zirconium