Computational Study of Cobalamin-Dependent Epoxyqueuosine Reductase: Formation of a Key Organometallic Intermediate with a "Stable-Yet-Fragile" Co-C Bond.

QueG is a cobalamin-dependent enzyme that catalyzes the epoxide reduction of queuosine (Q). The quantum chemical cluster approach has been performed to investigate the mechanism of the QueG-catalyzed reaction. Our calculations reveal a nucleophilic attack mechanism involving the formation of an intermediate with an unusual organometallic Co-C bond.

Sulfide Synthesis via A Bioinspired C-S σ-Bond Metathesis.

In this manuscript, inspired by the natural S-adenosylmethionine (SAM) cycle, we devised a mixed σ-bond metathesis between the (sp)C-S bond of organic sulfides with the C-O bond of alcohols. This reaction is mediated by a readily available and operationally facile mixture of AlCl and ZnI, which allows fast access to various challenging organic sulfides by directly editing the (sp)C-S bond of easily available ones. Like multiple bond metathesis, this method could also be rendered intramolecular and extended to ether (sp)C-O bond metathesis as well as amine (sp)C-N bond metathesis to provide saturated heterocycles such as cyclic thioethers, cyclic ethers, as well as cyclic amines.

Pivotal Role of Geometry Regulation on O-O Bond Formation Mechanism of Bimetallic Water Oxidation Catalysts.

In this study, we highlight the impact of catalyst geometry on the formation of O-O bonds in Cu and Fe catalysts. A series of Cu complexes with diverse linkers are designed as electrocatalysts for water oxidation. Interestingly, the catalytic performance of these Cu complexes is enhanced as their molecular skeletons become more rigid, which contrasts with the behavior observed in our previous investigation with Fe analogs.