Yoshihiro Nishimoto 교수

Site-selective and direct C-F bond transformation of perfluoroalkylarenes was achieved with allylic stannanes via an iridium photoredox catalyst system. The present defluoroallylation proceeds exclusively at the benzylic position through perfluoroalkyl radicals generated by a single-electron transfer from an excited photoredox catalyst to perfluoroalkylarenes. A variety of perfluoroalkyl groups are applicable: linear perfluoroalkyl-substituted arenes such as Ar-^<i>n</i>C₄F<

InBr(3) promotes the addition of ketene silyl acetals to monosubstituted alkynes to afford 2,2-disubstituted alkenylindium compounds in high regio- and stereoselectivity (see scheme). In addition, the alkenylindium derivatives have been subsequently coupled with iodobenzene in the presence of a palladium catalyst.

Three of new allosamidins, termed glucoallosamidins A (5), B (6) and methyl-N-demethyl-allosamidin (4), were isolated as yeast chitinase inhibitors from the mycelium of Streptomyces sp. SA-684.

The Friedel-Crafts acylation of arenes with esters by dimethylchlorosilane and 10 mol % of indium tribromide has been achieved. The key intermediate RCOOSi(Cl)Me(2) is generated from alkoxy esters with the evolution of the corresponding alkanes. The scope of the alkoxy ester moiety was wide: tert-butyl, benzyl, allyl, and isopropyl esters were successful. In addition, we demonstrated the direct synthesis of the indanone intermediate 11 of salviasperanol from ester 10.

A practical α-alkylation of ketones and aldehydes has been achieved by the direct addition of alcohols to enol acetates. The moderate Lewis acidity of InI3, GaBr3, and FeBr3 is a key factor in the catalytic cycle, and many different alcohols and enol acetates have been successfully used in this procedure. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submit

Indium halides or bismuth halides catalyzed the coupling of various alcohols with alkenylsilanes to give the corresponding alkenes stereospecifically without any other activators.

An indium triiodide-catalyzed substitution of the acetoxy group in alkyl acetates with thiosilanes provides access to a variety of thioethers. The method is efficient for a wide scope of acetates such as primary alkyl, secondary alkyl, tertiary alkyl, allylic, benzylic, and propargylic acetates.

Selective transformation of C-F bonds remains a significant goal in organic chemistry, but C-F insertion of a one-carbon-atom unit has never been established. Herein we report the BF₃-catalyzed formal insertion of diazo esters as one-carbon-atom sources into C-F bonds to accomplish one-carbon elongation of benzylic fluorides. A DFT calculation study revealed that the BF₃ catalyst could contribute to both C-F bond cleavage and re-formation. This elongation provided α-fluoro-

Indium(III) halide catalyzed not only the coupling of alkyl chlorides with silyl enolates derived from esters, ketones, and aldehydes to give a variety of alpha-alkylated carbonyl compounds but also one-pot, three-component reactions of aldehyde enolate, alkyl chloride, and allylsilane or alkynylsilane.

The cyclization of heteroatom-containing alkynes with π acidic metal salts is an attractive method to prepare heterocycles because the starting materials are readily available and the organometallic compounds are useful synthetic intermediates. A new organometallic species in the heterocyclization provides an opportunity to synthesize heterocycles that are difficult to obtain. Herein, we describe a novel cyclic oxymetalation of 2-alkynylbenzoate with indium or gallium salts that proceeds with an

The regioselective carboindation of simple alkenes with indium tribromide and ketene silyl acetals was accomplished. Various alkenes such as ethylene, 1-alkenes, and cyclic alkenes were applicable for this reaction system. The alkylindium product from the carboindation of cyclohexene revealed an anti addition mechanism.

Acylations achieved: The title reaction between carboxylic acids and ketene silyl acetals has been accomplished (see scheme). The additive, (MeO)3SiH, is believed to play an important role in the promotion of the condensation reaction. This reaction system was compatible with a diverse range of functional groups, including alkenes, alkynes, chlorides, alcohols, esters, and nitro groups.

A ‘Ga'llant couple: The α-alkenylation of esters was accomplished by GaBr3-catalyzed coupling between alkenyl ethers and ketene silyl acetals. In this reaction system, various alkenyl ethers, including those with vinyl and substituted alkenyl groups, were applicable, and the scope of applicable ketene silyl acetals was sufficiently broad. The mechanism is also discussed.

Three become one: The first carbobismuthination of alkynes has been accomplished by the simple reaction of an alkyne, BiBr3, and a ketene silyl acetal to produce an alkenylbismuth with high stereo- and regioselectivity (see scheme). X-ray crystallographic analysis of the alkenylbismuth product and control experiments using α-bismuthino ester revealed the reaction mechanism.