Catalysis of symmetry-restricted reactions by transition metal compounds. Valence isomerization of cubane

Metal-Assisted Cycloaddition Reactions in Organotransition Metal Chemistry

“…As opposed to these reactions, the metal-induced (mostly with Rh(I)), stoichiometric 215 or catalytic 216,217 ring-opening reactions of strained cyclobutanes to the formal [2+2] cycloreversion products proceed by an oxidative addition (insertion of the metal into the strained C-C bond)/reductive elimination sequence. Heteroatom-stabilized carbene complexes react with isonitriles to give ketenimine complexes 113.…”

Molecular Electrostatic Potentials and Chemical Reactivity

“…In the cases of cubane, 45, and homocubane, 46, their negative bond regions help to explain their observed cation-catalyzed rearrangements, in which the initial step is an interaction between the positive ion and a G-C bond. [165][166][167][168] A well-established approach for studying the bonds in strained molecules is by means of the bond path c o n~e p t . '~~-'~~ A bond path corresponds to the ridge of highest electron density that links two nuclei.…”

Cubane: 50 Years Later

“…This has been postulated to go through a C−C bond insertion (132) followed by a 2-fold carbodemetalation event (Scheme 36). 10, 106 Another remarkable discovery was made by the same group in the same year. 106 In the presence of silver(I) salts and palladium(II) salts, cubane (1) undergoes a cation-cascade rearrangement to furnish cuneane (136).…”

“…10, 106 Another remarkable discovery was made by the same group in the same year. 106 In the presence of silver(I) salts and palladium(II) salts, cubane (1) undergoes a cation-cascade rearrangement to furnish cuneane (136). Shown in the context of AgClO 4 as catalyst, it was proposed that there is an initial cleavage of a carbon−carbon bond (134) in the cubane core followed by skeletal rearrangement to give cuneane (136; Scheme 37).…”