Synthesis and Reactivity of the Methylene Arenium Form of a Benzyl Cation, Stabilized by Complexation
作者:Elena Poverenov、Gregory Leitus、David Milstein
DOI:10.1021/ja067298z
日期:2006.12.1
Benzyl cations are unstable intermediates involved in various chemical and biological processes. Two extreme resonance forms of these cations include positive charge localization at the methylene carbon or delocalization in the ring, the latter, nonaromatic form, termed "methylene arenium". The preparation of the discrete methylene arenium compound, stabilized by coordination to a metal (palladium) center, is described. It was fully characterized, including by X-ray diffraction. Reactivity patterns, resulting from charge distribution in the ring, were observed. Upon controlled release of the methylene arenium compound into solution, it demonstrates aromatic benzyl cation reactivity.
Benzyl Cation Stabilized by Metal Complexation. Relative Stability of Coordinated Methylene Arenium, π-Benzylic, and σ-Benzylic Structures
作者:Elena Poverenov、Irena Efremenko、Gregory Leitus、Jan M. L. Martin、David Milstein
DOI:10.1021/om400523f
日期:2013.9.9
Benzyl cations are highly reactive compounds involved as intermediates in various chemical and biochemical processes. In this work metal coordination was utilized to stabilize different coordinated modes of benzyl cations, including methylene arenium (MA), π-benzyl, and σ-benzyl complexes. Two bidentate ligand frameworks, diphenylphosphinoethane (dppe) and di-tert-butylphosphinopropane (dtpp), were