Photoredox-catalyzed 1,2-oxo-alkylation of vinyl arenes with 1,3-diketones: an approach to 1,4-dicarbonyls C-C activation.

A mild and inexpensive approach to synthesising a series of 1,4-diketones in moderate to excellent yields 1,2-oxo alkylation has been developed using fluorescein as a photocatalyst and air as an oxidant. The key features include (i) varied substrate scope (39 examples); (ii) good functional group tolerance; (iii) unsymmetrical 1,4-dicarbonyls; (iv) late-stage functionalization of thymol and ibuprofen derivatives; and (v) the synthetic expansion to 5- and 6-membered N-, O- and S-containing heterocycles.

Metal-Free Synthesis of Benzimidazoles via Oxidative Cyclization of d-Glucose with -Phenylenediamines in Water.

d-Glucose has been identified as an efficient C1 synthon in the synthesis of benzimidazoles from -phenylenediamines via an oxidative cyclization strategy. Isotopic studies with C-d-glucose and DO unambiguously confirmed the source of methine. The notable features of this method include the following: broad functional group tolerance, a biorenewable methine source, excellent reaction yields, a short reaction time, water as an environmentally benign solvent, and the synthesis of vitamin component on the gram scale.