A new protocol was developed to synthesize (enantioenriched) thioethers and selenoethersfrom (chiral) benzylic trimethylammonium salts and di(hetero)aryl disulfides or diselenides. These syntheses were promoted by the presence of weak base and did not require the use of any transition metal, and resulted in the target products with good to excellent yields (72–94%). Using quaternary ammonium salts
bibenzyls and related ethane derivatives in high yields. Other diselenides were easily caused to cleave to give various aromatic and aliphatic olefins in good yields together with elemental selenium. Lepidopterene, [2.2]paracyclophane, and benzocyclobutene were prepared by thermal cleavage of their corresponding phenylselenomethyl-substituted compounds as an application of the pyrolysis concerned.
We report the first metal-free selenolations of pyridinium salts with diselenides to prepare unsymmetrical organoselenides catalysed by visible light. This protocol is an efficient and green method for the preparation of unsymmetrical organoselenides because metal-free conditions and readily accessible diselenides are used.
The flash vacuum pyrolysis of benzyl phenyl selenides gave bibenzyls and diphenyl diselenide in excellent yields. This type of reaction was successfully applied to the synthesis of the title compounds.
An iridium-catalyzed selenium-directed ortho-C–H borylation of benzyl selenide derivatives was successfully developed. This is the first example where selenium is used as a directing group in C–H borylation. The reaction was carried out using the tricyclohexylphosphine ligand for an improved catalytic efficiency. Various substrates were tolerated and afforded either ortho-monoborylated products (substrates