Cage-Walking: Vertex Differentiation by Palladium-Catalyzed Isomerization of B(9)-Bromo-meta-Carborane
- 1 June 2017
- journal article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 139 (23), 7729-7732
- https://doi.org/10.1021/jacs.7b04080
Abstract
We report the first observed Pd-catalyzed isomerization ("cage-walking") of B(9)-bromo-meta-carborane during Pd-catalyzed cross-coupling, which enables the formation of B-O and B-N bonds at all boron vertices (B(2), B(4), B(5), and B(9)) of meta-carborane. Experimental and theoretical studies suggest this isomerization mechanism is strongly influenced by the steric crowding at the Pd catalyst by either a biaryl phosphine ligand and/or substrate. Ultimately, this "cage-walking" process provides a unique pathway to preferentially introduce functional groups at the B(2) vertex using B(9)-bromo-meta-carborane as the sole starting material through substrate control.Funding Information
- Division of Chemistry (CHE-1048804, CHE1361104)
- University of California, Los Angeles
- U.S. Department of Defense
- American Chemical Society Petroleum Research Fund (56562-DNI3)
- 3M
This publication has 47 references indexed in Scilit:
- Studying Regioisomer Formation in the Pd-Catalyzed Fluorination of Aryl Triflates by Deuterium LabelingJournal of the American Chemical Society, 2014
- Palladium(II)-Catalyzed Rearrangement and Oligomerization Reactions of cis-Bicyclo[4.2.0]oct-7-eneOrganometallics, 2012
- Weak Coordination as a Powerful Means for Developing Broadly Useful C–H Functionalization ReactionsAccounts of Chemical Research, 2011
- Extensive Isomerization of Alkenes Using a Bifunctional Catalyst: An Alkene ZipperJournal of the American Chemical Society, 2007
- Measurement of the Barrier to β-Hydride Elimination in a β-Agostic Palladium−Ethyl Complex: A Model for the Energetics of Chain-Walking in (α-Diimine)PdR+ Olefin Polymerization CatalystsOrganometallics, 2001
- Mechanistic Studies of Pd(II)−α-Diimine-Catalyzed Olefin Polymerizations1Journal of the American Chemical Society, 2000
- Chain Walking: A New Strategy to Control Polymer TopologyScience, 1999
- Transition-Metal Complexes of Arynes, Strained Cyclic Alkynes, and Strained Cyclic CumulenesAdvances in Organometallic Chemistry, 1998
- Structure, synthesis, and chemistry of ruthenium complex (PMe3)4Ru(.eta.2-benzyne). Reactions with arenes, alkenes, and heteroatom-containing organic compounds. Synthesis and structure of a monomeric hydroxide complexJournal of the American Chemical Society, 1991
- Group 4 metal complexes of benzynes, cycloalkynes, acyclic alkynes, and alkenesChemical Reviews, 1988