Katsukiyo Miura

TRIETHYLBORANE INDUCED PERFLUOROALKYLATION OF SILYL ENOL ETHERS OR GERMYL ENOL ETHERS WITH PERFLUOROALKYL IODIDES

Abstract Reaction of perfluoroalkyl iodides with silyl enol ethers mediated by Et 3 B in the presence of a base provides perfluoroalkylated silyl enol ethers. Meanwhile, treatment of germyl enol ethers with perfluoroalkyl iodides affords β-perfluoroalkyl ketones in good yields.

Synthesis of vinylcyclopentanes from vinylcyclopropanes and alkenes promoted by benzenethiyl radical

Abstract The reaction of dimethyl 2-vinylcyclopropane-1,1-dicarboxylate with butyl vinyl ether in the presence of a catalytic amount of PhSH provides dimethyl 3-butoxy-4-vinylcyclopentane-1,1-dicarboxylate in 82% yield.

tert-Butyldimethylsilyldihalomethyllithium as a dihalomethylene dianion synthon. 1,3-Rearrangement and 1,4-rearrangement of silyl group from carbon to oxide

Abstract One-pot synthesis of R 1 CH(OSiMe 2 - t -Bu)CX 2 CH(OH)R 2 (X=Cl, Br) successive addition of two different aldehydes (R 1 CHO and R 2 CHO) has been achieved starting from tert -butyldimethylsilyldihalomethyllithium. Treatment of a THF solution of the title carbanion (X=Cl) with p -MeOC 6 H 4 CHO or n -BuCHO followed by an addition of HMPA and benzaldehyde gave the corresponding 1,3-diol monosilyl ether in 83% or 45% yield, respectively. The use of oxirane in place of aldehyde as the first electrophile followed by addition of benzaldehyde provided 1,4-diol monosilyl ether.

Triprenylstannyl radical or benzenethiyl radical promotedtransformation of 1,1-dialk oxycarronyl-2-(1,3-butadienyl)cyclopropanes into 2-ethenyl-3-cyclopentenes

Abstract Dimethyl 2-(1,3-butadienyl)cyclopropane-1,1-dicarboxylate reacts with catalytic amount of Ph3SnH in benzene at 80°C to provide dimethyl 2-ethenyl-3-cyclopentene-1,1-dicarboxylate in good yield. The transformation of N-tosyl-2-(1,3-butadienyl)aziridine into N-tosyl-2-vinyl-3-pyrroline is also described.

Transformation of n-tosyl-2-(1,3-butadienyl)aziridine into n-tosyl-2-ethenyl-3-pyrroline

Abstract 1,3-Butadienylaziridines or 1,3-butadienylazetidines activated by N-tosyl group smoothly rearrange to vinylpyrroline derivatives or vinylpiperidines in the presence of a catalytic amount of Pd(PPh 3 ) 4 . Triphenyltin radical induced rearrangement of title compounds is also described.

Radical cyclization of 1-allyloxy-2-halo-1-silacyclopentane. Application to stereoselective synthesis of 1,4,6-triols

Treatment of 1-allyloxy-1-phenyl-2-bromo-1-silacyclopentane with n-Bu3SnH in the presence of catalytic amount of Et3B provided 1-sila-2-oxabicyclo[3.3.0]-octane which was converted into 1,4,6-triol.

Potassium t-butoxide or silver acetate induced ring enlargement of silacyclobutane into silacyclopentane. Application to the Synthesis of 1,4-Diol

Abstract Treatment of 1-(1-iodoalkyl)-1-silacyclobutanes with t-BuOK or AgOAc provided 2-alkyl-1-silacyclopentanes which were easily converted into 1,4-diols by oxidative cleavage of carbonsilicon bonds.

Stabilizing effect of trialkylsilyl group on carbon radical: Radical induced ring opening of 1-trialkylsilyl-2-vinylcyclopropanes

Abstract 1-Trialkylsilyl-2-vinylcyclopropane or 3-methyl-1-trialkylsilyl-2-vinylcyclopropane provided the corresponding homoallylic silane exclusively upon treatment with PhSH, Ph 3 SnH, or C 6 F 13 I. On the other hand, 3-phenyl-1-trimethylsilyl-2-vinylcyclopropane or 3-acetyl-1-trimethylsilyl-2-vinylcyclopropane gave allylic silane selectively.