Hideyoshi Miyake

A new synthetic method: Direct replacement of the nitro group by hydrogen or deuterium

Abstract The nitro group in tertiary or secondary aliphatic nitro compounds is replaced by hydrogen or deuterium on treatment with tributyltin hydride or tributyltin deuteride, respectively.

Denitrohydrogenation of aliphatic nitro compounds and a new use of aliphatic nitro compounds as radical precursors

Abstract Aliphatic nitro groups are replaced by hydrogen on treatment with tributyltin hydride which proceeds via free radical chain processes. As the nitro group is selectively denitrated and other reducible groups are not affected with tributyltin hydride, this reaction can be used as a method for removing the nitro group from polyfunctional compounds. The radical intermediates generated via denitration can be also used for the carbon-carbon bond forming reactions.

Synthesis and Seed Germination Stimulating Activity of Some Imino Analogs of Strigolactones

Strigolactones are germination stimulants for seeds of the root parasitic weeds, Striga and Orobanche spp. The imino analog of GR24 showed moderate germination stimulating activity against the seeds of S. hermonthica. The seed germination stimulating activity of some phenyliminoacetates and phenyliminoacetonitriles was also examined. The degree of activity of the phenyliminoacetate was less than that of the phenylacrylates. On the other hand, the degree of activity of the phenyliminoacetonitrile was comparable to that of the phenylacrylonitriles. Among the tested compounds, the 3-pyridyliminoacetonitrile showed higher activity against the seeds of O. crenata than GR24. These findings demonstrate that it is not always essential to have the Michael acceptor of the C–D ring junction moiety which has been proposed to react with nucleophilic species presented at the target site to enhance the activity.

Conjugate addition of alkyl groups to α,β-unsaturated sulfoxides via Michael addition of nitroparaffins and subsequent denitration with tributyltin hydride

Abstract Michael addition of nitroparaffins to α,β-unsaturated sulfoxides is well effected in the presence of DBU. The nitro group in the adduct is replaced by hydrogen with Bu 3 SnH without influence to the sulfinyl function. The overall reations provide an efficient method for the conjugate addition of alkyl groups to α,β-unsaturated sulfoxides.

A new synthesis of α-methylene carbonyl compounds

Abstract α-Methylene carbonyl compounds are regioselectively prepared by the reaction of α-nitroketones or α-nitroesters with 37% formaldehyde in the presence of a catalytic amount of weak bases followed by acetylation, denitration with Bu 3 SnH, and elimination of acetic acid.

Regioselective Diels–Alder reactions. The nitro group as a regiochemical control element

The sequence of the Diels–Alder reaction of α-nitroalkenes with dienes and subsequent denitration with Bu3SnH provides a new method for the regioselective construction of cyclohexene derivatives.

A novel synthesis of β-(10-benz[a]azulenyl)-α,β-unsaturated ketones by intramolecular cyclization of o-[2-furyl]cycloheptatrienylbenzenes

Abstract Treatment of o -[2-furyl]cycloheptatrienylbenzenes with triphenylmethyl tetrafluoroborate (trityl salt) in dichloromethane gave β -(10-benz[ a ]azulenyl)-α,β-unsaturated ketones in one-pot, in which a novel cyclization involving intramolecular attack of tropylium ion to the α-position of furan ring is postulated.

Regioselective construction of cyclohexene derivatives by Diels–Alder reactions of nitro-olefins with dienes and subsequent denitration with tributyltin hydride

The nitro-group in the Diels–Alder adducts of nitro-olefins with dienes is replaced by hydrogen on treatment with tributyltin hydride, which offers a new method for the regioselective construction of cyclohexene derivatives.

Lewis acid catalyzed substitution of allylic nitro compounds with cyanotrimethylsilane

Abstract The nitro group in allylic nitro compounds is replaced by cyano group on treatment with cyanotrimethylsilane in the presence of Lewis acid.

A new synthesis of 1,5-dicarbonyl compounds under neutral conditions

Michael addition of α-nitroketones to methyl vinyl ketone or acrylaldehyde followed by denitration with Bu3SnH affords 1,5-dicarbonyl compounds in good yields.