Tomoaki Yamaguchi

Molecular-iodine-catalyzed aerobic oxidative synthesis of β-hydroxy sulfones from alkenes

The synthesis of β-hydroxy sulfones from alkenes and sodium sulfinates under aerobic oxidative conditions was achieved in the presence of a catalytic amount of molecular iodine. Molecular oxygen in air serves as the terminal oxidant and the catalytic amount of molecular iodine acts as the sulfonyl radical initiator and peroxide reductant.

Molecular-iodine-catalyzed aerobic photooxidative C–C bond formation between tertiary amines and carbon nucleophiles

This paper reports a useful method for molecular-iodine-catalyzed aerobic photooxidative C–C bond formation between tertiary amines and carbon nucleophiles. This reaction provides a practical method for C–C bond formation through the use of molecular iodine, harmless visible light irradiation, and molecular oxygen as the terminal oxidant.

Cross-Dehydrogenative C-H Amination of Indoles under Aerobic Photo-oxidative Conditions

A novel cross-dehydrogenative C(sp2)-H amination catalyzed by an organic photocatalyst is reported. The reaction is mediated by 2-tert-butylanthraquinone as a photocatalyst, harmless visible light, and aerobic oxygen as the sole oxidant without a transition-metal catalyst and or external oxidant.

Magnesium iodide-catalyzed synthesis of 2-substituted quinazolines using molecular oxygen and visible light

A novel and efficient approach for the synthesis of quinazolines by aerobic photooxidation with an iodine reagent at room temperature is reported. This method uses harmless visible light from compact fluorescent lamps and molecular oxygen as the sole oxidant without the need for a transition-metal catalyst or harsh reaction conditions.

Photoinduced Generation of Acyl Radicals from Simple Aldehydes, Access to 3-Acyl-4-arylcoumarin Derivatives, and Evaluation of Their Antiandrogenic Activities

A novel photocatalysis to construct the 3-acyl-4-arylcoumarin framework from simple aldehyde with ynoate is described. The reaction proceeded through an acyl radical intermediate generated by hydrogen atom abstraction from aldehyde, followed by reaction with ynoate and then cyclization to afford coumarins. This valuable radical cyclization reaction gave over 20 coumarin derivatives in moderate to good yields with inexpensive 2-tBu-anthraquinone as a catalyst. In addition, synthetic coumarins were investigated for 5α-dihydrotestosterone (DHT)-induced secretion of prostate-specific antigen (PSA) levels and cell proliferation of androgen-dependent CWR22Rv1 cells.

Synthesis of 2-hydroxymalonic acid derivatives via tandem oxidation and rearrangement by photo organic catalysis

This report describes a mild method for the direct transformation of β-oxoesters to the corresponding 2-hydroxymalonic esters, tartronic esters, using singlet oxygen produced by a catalytic amount of methylene blue and visible light irradiation using fluorescent lamps. In addition, β-oxoamides were also converted to the corresponding 2-hydroxymalonic ester amides.