10.1039/b313491a
The research examines the thermal decomposition of various O-benzyl ketoxime ethers (R1R2C(NOCH2Ph)) in three hydrogen donor solvents: tetralin, 9,10-dihydrophenanthrene (DHP), and 9,10-dihydroanthracene (DHA). The study aims to understand the dominant homolytic cleavage modes and the effects of substituents and solvents on the dissociation processes. The results show that the yields of products like imines and benzyl alcohol varied with the solvent, indicating significant involvement of reverse radical disproportionation (RRD) in DHP and DHA, where hydrogen atoms from the solvent transfer to the oxime ethers, followed by β-scission of the resultant radicals. In tetralin, an additional product, benzaldehyde, was observed, suggesting an alternative decomposition mode involving benzylic hydrogen abstraction. The study concludes that the RRD process plays a crucial role in the thermal decomposition of these oxime ethers in certain solvents, and the rates of decomposition and product yields are influenced by both the nature of the substituents and the solvent used.
10.1021/om00136a015
The research focuses on the reduction of metal carbonyls via electron transfer, specifically examining the formation and decomposition of formylmetal intermediates. The study aims to understand the processes involved when metal carbonyls such as Cr(CO)6 and Fe(CO)5 are reduced, leading to the formation of 19-electron anion radicals that can be trapped by hydrogen atom donors to form formylmetal carbonyls. The research concludes that the formylmetal carbonyls are subject to radical-chain decomposition, the mechanism of which is established through a detailed study of the formyldirhenate complex. The study reveals that the decomposition is kinetically controlled and can be enhanced under radical, photochemical, electrochemical, and reductive conditions. The chemicals used in this process include metal carbonyls like Cr(CO)6, Fe(CO)5, Mn(CO)4(PPh3)2+PF6-, and Re2(CO)10, as well as reducing agents like tri-n-butyltin hydride and sodium anthracene, and additives such as AIBN and dihydroanthracene. The research provides insights into the stabilization of formylmetal complexes by various hydrogen atom donors, demonstrating the generality of the radical-chain process in the decomposition of these organometallic intermediates.