Norihiro Tada

Molecular Iodine Catalyzed Cross-Dehydrogenative Coupling Reaction between Two sp3 C–H Bonds Using Hydrogen Peroxide

A useful method for molecular iodine catalyzed oxidative C-C bond formation between tertiary amines and a carbon nucleophile using hydrogen peroxide as the terminal oxidant is reported. This is the first report of a molecular iodine catalyzed cross-dehydrogenative coupling (CDC) reaction between two sp(3) C-H bonds.

Direct asymmetric aldol reaction with recyclable fluorous organocatalyst.

Direct asymmetric aldol reactions of aldehydes with ketones in the presence of a catalytic amount of fluorous sulfonamide 4 and trifluoroacetic acid result in the corresponding aldol products in high yields with up to 96% ee. The fluorous organocatalyst 4 can be readily recovered from the reaction mixture by fluorous solid-phase extraction and could be reused without a significant loss of the catalytic activity and enantioselectivity.

Direct Aerobic Photo-Oxidative Synthesis of Aromatic Methyl Esters from Methyl Aromatics via Dimethyl Acetals

A useful method for facile synthesis of aromatic methyl esters from methyl aromatics via dimethyl acetals by aerobic photo-oxidation using inexpensive and easily handled CBr(4) as catalyst is reported. This is the first example for direct preparation of the corresponding aromatic methyl esters from methyl aromatics.

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.

Facile aerobic photooxidation of methyl group in the aromatic nucleus in the presence of an organocatalyst under VIS irradiation

We report a useful method for a facile synthesis of carboxylic acids from methyl aromatics by aerobic photooxidation using VIS irradiation and easily handled 2-chloroanthraquinone as organic catalysts under mild conditions such as an air atmosphere and ambient pressure and temperature. This is a more environmentally benign oxidation than previous methods, which require drastic reaction conditions.

Tandem oxidation/rearrangement of beta-ketoesters to tartronic esters with molecular oxygen catalyzed by calcium iodide under visible light irradiation with fluorescent lamp.

It was found that beta-ketoesters were directly transformed to the corresponding alpha-hydroxymalonic esters, tartronic esters, with molecular oxygen catalyzed by calcium iodide under visible light irradiation from fluorescent lamp. This reaction includes tandem oxidation/rearrangement and has received much attention from the viewpoint of reduction of energy consumption, labor, and solvents.

Thermal and catalytic transylidations between halonium ylides and synthesis and reaction of stable aliphatic chloronium ylides

Intermolecular transylidation between halonium ylides under thermal and catalytic (rhodium(II) acetate) conditions, which makes it possible to synthesize a hitherto unknown kind of aliphatic chloronium ylides as well as a variety of bromonium and iodonium ylides, was developed. The uncatalyzed thermal transylidations of bromonium to iodonium ylides probably involve generation of a reactive carbene :C(SO2CF3)2, being electrophilic in nature. Compared to the bromonium and iodonium ylides, the chloronium ylide serves as a much better progenitor for generation of carbenes (or carbenoids) and efficiently undergoes cyclopropanation of olefins such as cyclooctadiene under uncatalyzed thermal conditions. A greater leaving group ability of the λ3-chloranyl and λ3-bromanyl groups compared to that of the λ3-iodanyl group seems to be responsible for the observed differences in reactivity between these halonium ylides.

One-pot metal-free syntheses of acetophenones from styrenes through aerobic photo-oxidation and deiodination with iodine.

A one-pot synthetic protocol of acetophenones from styrenes with molecular oxygen, visible light, and molecular iodine is reported. This procedure involves aerobic photo-oxidation and deiodination in one pot and provides the first report of metal-free direct syntheses of acetophenones from styrenes.

Sequential Photo-oxidative [3 + 2] Cycloaddition/Oxidative Aromatization Reactions for the Synthesis of Pyrrolo[2,1-a]isoquinolines Using Molecular Oxygen as the Terminal Oxidant

We report an efficient method for the synthesis of pyrrolo[2,1-a]isoquinoline derivatives using sequential [3 + 2] cycloaddition/oxidative aromatization reactions catalyzed by methylene blue with fluorescent light irradiation under an oxygen atmosphere. The products were obtained in moderate to good yields.

Direct aerobic photo-oxidative syntheses of aromatic methyl esters from methyl aromatics using anthraquinone-2,3-dicarboxylic acid as organophotocatalyst

This paper reports a useful method for facile direct syntheses of aromatic methyl esters from methyl aromatics by aerobic photo-oxidation using anthraquinone-2,3-dicarboxylic acid as an organophotocatalyst.