Hidenobu Ohmori

Cyclization of vinyl and aryl radicals generated by a nickel(II) complex catalysed electroreduction

Abstract Radical cyclization of vinyl and aryl halides was performed by indirect electroreduction using a nickel(II) complex as a catalyst.

Reactions of acyl tributylphosphonium chlorides and dialkyl acylphosphonates with Grignard and organolithium reagents

Abstract Ketones and esters ( 4 ) were effectively prepared by reaction of Grignard reagents with acyl tributylphosphonium chlorides ( 2 ), diethyl acylphosphonates ( 5 ), or diisopropyl acylphosphonate ( 6 ) derived from acid chlorides and chloroformates ( 1 ). Although by the method with 2 , 4 is prepared in one-pot operation from 1 and generally in a higher yield, the method with 5 or 6 proved to compensate for the synthesis of 4 with 2 in some respects. The reactivities of 2 , 5 , and 6 as electrophiles were also evaluated by comparing their reduction potentials with those of acid chlorides.

Cyclopropanation by tandem radical [2 + 1] cycloaddition conducted by nickel complexes catalyzed electroreduction

Abstract Bicyclo[3. 1. 0]-, 3-azabicyclo [3. 1. 0]- and 3-oxabicyclo[3. 1. 0]hexane derivatives were prepared by a nickel complex catalyzed elctroreduction of 2-bromo or 2-iodo-1, 6-diene derivatives.

Reactions of in situ formed acyl tributylphosphonium ions with Grignard reagents as an effective route to ketones from acid chlorides

Abstract The reactions of acyl tributylphosphonium ions in situ generated from acid chlorides and Bu 3 P in THF at −22°C with primary alkyl and arylmagnesium halides have proved to be a convenient and simple procedure to prepare ketones from acid chloride in one-pot.

Reaction of triphenylphosphine radical cation with cycloalkenes: electrochemical one-step preparation of 1-cycloalkenyltriphenylphosphonium salts

Abstract Constant current electrolysis of triphenylphosphine in dichloromethane at a graphite anode in the presence of cycloalkenes gave the corresponding 1-cycloalkenylphosphonium salts in reasonable yields.

2H NMR study of the self-assembly of an azo dye-cyclomaltooctaose (γ-cyclodextrin) complex

Abstract Orange II and γ-cyclodextrin form 2:1 and 2:2 complexes. These complexes self-associate, and microscopic viewing indicates the formation of a fibroid aggregate. The deuteron resonance (in 2 H NMR spectroscopy) from deuteron exchange and solvation between the aggregate and deuterium oxide exhibits quadrupole splitting (Δν) in the region of 0-1.2 KHz. The orientation behavior obtained from this splitting suggests the formation of a liquid-crystaloid substance. (1) The aggregate aligned by means of the super conductive and permanent magnetic fields shows a different NMR pattern and turbidity. (2) Dilution of the 0.12 M aggregate with deuterium oxide proceeds discontinuously via the nonoriented pattern to the oriented-pattern. (3) With an increase in temperature, the 2 H NMR spin-spin splitting values decrease continuously. A phase diagram that plots melting points in variable concentrations reveals separate solution and aggregate layers. (4) When the 0.06 M aggregate is diluted by deuterated solvents (water, methanol, ethanol, propanol, dimethyl sulfoxide, and acetone), increases in the amount added and the length of solvent molecules cause a regular reduction of Δν. The deuterium signal of the methyl group in dimethyl sulfoxide- d 6 exhibits a small Δν, suggesting that this solvent is included in the orientation system.

SYNTHESIS OF CYCLIC SULFIDES BY NICKEL COMPLEXES CATALYZED ELECTROREDUCTION OF UNSATURATED THIOACETATES AND THIOSULFONATES

Abstract Functionalized cyclic sulfides with four to six membered rings were synthesized by ring closure of the labile thiols which were formed in situ by the nickel complex catalyzed electroreduction of the thioacetates and thiosulfonates having suitably placed electrophilic olefins or acetylenes.

One-step transformation of α-amino acids to α-amino aldehydes effected by electrochemical oxidation of Ph3P

Abstract The electrolysis of triphenylphosphine and L-α-amino acids in one compartment cell under a nitrogen atmosphere at −30°C gave L-α-amino aldehydes in good yields with no or little racemization when triphenylphosphonium perchlorate was used as a supporting electrolyte.

Electrochemical generation and reactions of acyloxytriphenylphosphonium ions

Abstract Constant-current electrolysis, in an undivided cell, of Ph3P in the presence of a carboxylic acid in CH2Cl2 containing 2,6-lutidinium perchlorate as the supporting electrolyte was shown to generate the corresponding acyloxyphosphonium ion, Ph3P+-OCOR, which was converted in situ to esters, amides, and β-lactams under mild conditions.

TRANSFORMATION OF ACID CHLORIDES INTO ALDEHYDES BY REDUCTION OF IN-SITU FORMED ACYLTRIBUTYLPHOSPHONIUM IONS WITH ZINC-COPPER COUPLE OR ZINC

Abstract Transformation of acid chlorides into the corresponding aldehydes without over-reduction to alcohols was effectively achieved by the reduction of acyltributylphosphonium ions, formed in-situ from the chlorides and tributylphosphine in CH 3 CN, with ZnCu couple or Zn in the presence of CH 3 SO 3 H under an N 2 atmosphere.