title: Duality of Orbital-Symmetry-Allowed Transition States for Thermal Sigmatropic Hydrogen Shifts in Transition Metal Compounds.
abstract: Herein, the Zimmerman Möbius/Hückel concept is extended to pericyclic reactions involving transition metals. While sigmatropic hydrogen shifts in parent hydrocarbons are either uniquely antarafacial or suprafacial, we have shown by theoretical orbital topology considerations and quantum chemical computations at DFT level that both modes of stereoselectivity must become allowed in the same system as a consequence of Craig-Möbius-type orbital arrays, in which a transition metal d orbital induces a phase dislocation in metallacycles. This may have fundamental implications for the understanding of reactivity and bonding in organometallic chemistry.
authors: Department of Chemistry and Pharmacy, Institute of Theoretical Chemistry, Computer Chemistry Center, Nägelsbachstrasse 25a, 91052, Erlangen, Germany. michael.mauksch@fau.de.
authors: Michael
authors: M
authors: Mauksch
authors: Department of Chemistry and Pharmacy, Organic Chemistry Chair I and Interdisciplinary Center for Molecular Materials, Friedrich-Alexander-Universität Erlangen-Nürnberg, Henkestrasse 42, 91054, Erlangen, Germany. svetlana.tsogoeva@fau.de.
authors: Svetlana B
authors: SB
authors: Tsogoeva
keywords: coordination chemistry; organometallic reactions; pericyclic reactions; stereoselectivity; transition states