Aritsune Kaji

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.

β-Sulfonylnitroolefins as very reactive alkyne-equivalents in Diels-Alder reactions

Abstract Very reactive dienophiles, β-sulfonylnitroolefins, are prepared starting from β-nitro alcohols. The high activation due to the nitro and the sulfonyl groups promotes the Diels-Alder reaction to various dienes under mild conditions. Reductive elimination of the adduct with Bu 3 SnH gives cyclic 1,4-dienes.

A new synthesis of allylic alcohols or their derivatives via reductive elimination from γ-phenylthio-β-nitroalcohols with tributyltinhydride

Abstract Allylic alcohols are readily prepared by the Bu 3 SnH-promoted elimination reaction from γ-phenylthio-β-nitroalcohls which are obtained by the joint reaction of nitroolefins, thiophenol, and aldehydes.

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.

Stereochemistry in alkylations of dianions of β-hydroxysulfoxides and β-hydroxysulfones

Abstract Alkylations of dianions of β-hydroxysulfoxides and β-hydroxysulfones have been found to be affected by chelation of a Li cation with a sulfinyl group and by coordination of the cation with tetrahydrofuran rather than a sulfonyl group, respectively.

Asymmetric synthesis of γ-alkayl-α-methylene-γ-butyrolactones via 1,6-remote induction using 2-[(tributylstannyl) methyl]propenamides

Abstract Reaction of chiral 2-[(tributylstannyl)methyl]propenamides with aldehydes proceeded with 1,6-asymmetric induction to give, after hydrolysis, α,-methylene-γ-butyrolactones in enantiomeric excesses as high as 80%.

A new olefin synthesis. Synchronous elimination of nitro and ester groups or nitro and keto groups from .beta.-nitro esters or .beta.-nitro ketones

Synthese de nitriles, esters, cetones et sulfones vinyliques a partir de (chloro-1 nitro-1) ou de (bromo-1 nitro-1) alcanes