26878-12-6Relevant articles and documents
Migratory Insertion of Carbenes into Au(III)-C Bonds
Zhukhovitskiy, Aleksandr V.,Kobylianskii, Ilia J.,Wu, Chung-Yeh,Toste, F. Dean
supporting information, p. 466 - 474 (2018/03/21)
Migratory insertion of carbon-based species into transition-metal-carbon bonds is a mechanistic manifold of vast significance: it underlies the Fischer-Tropsch process, Mizoroki-Heck reaction, Ziegler-Natta and analogous late-transition-metal-catalyzed olefin polymerizations, and a number of carbonylative methods for the synthesis of ketones and esters, among others. Although this type of reactivity is well-precedented for most transition metals, gold constitutes a notable exception, with virtually no well-characterized examples known to date. Yet, the complementary reactivity of gold to numerous other transition metals would offer new synthetic opportunities for migratory insertion of carbon-based species into gold-carbon bonds. Here we report the discovery of well-defined Au(III) complexes that participate in rapid migratory insertion of carbenes derived from silyl- or carbonyl-stabilized diazoalkanes into Au-C bonds at temperatures ≥ -40 °C. Through a combined theoretical and experimental approach, key kinetic, thermodynamic, and structural details of this reaction manifold were elucidated. This study paves the way for homogeneous gold-catalyzed processes incorporating carbene migratory insertion steps.
Orbital distortion arising from remote substituents. Nitration, reduction, and epoxidation of fluorenes bearing a carbonyl or an olefin group in spiro geometry
Ohwada, Tomohiko
, p. 8818 - 8827 (2007/10/02)
Nitration of spiro[cyclopentane-1,9′-fluoren]-2-one with acetyl nitrate predominantly gave the 4-nitro derivative. In the reduction of substituted spiro[cyclopntane-1,9′-fluoren]-2-ones, the anti alcohols were favored in all cases. In the epoxidation of substituted spiro[cyclopent-2-ene-1,9′-fluorenes], the syn epoxides were favored. These distributions of the products can be interpreted in terms of orbital perturbations arising from interactions of the π orbitals of the aromatic and the carbonyl moieties or of the π orbitals of the aromatic and the olefin moieties, i.e., orbital mixing perturbation of the aromatic π orbitals through the π orbital of the bisected carbonyl (or olefin) group and the reciprocal perturbation of the π orbital of the carbonyl (or olefin) group arising from the orthogonal π aromatic orbitals.
