Fumiaki Iwasaki

4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methyl-morpholinium chloride: an efficient condensing agent leading to the formation of amides and esters

Abstract 4-(4,6-Dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) was quantitatively synthesized by the coupling of 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT) and N-methylmorpholine (NMM) in THF, and characterized. Condensation of carboxylic acids and amines by DMTMM proceeded effectively in THF to give the corresponding amides in good yields. The corresponding esters can be obtained by esterification of caiboxylic acids with DMTMM in methanol, ethanol, isopropy1 alcohol, or t-butyl alcohol in the presence of NMM. The amount of alcohols can be reduced to a stoichiometric amount by conducting the reaction in THF. Since the reactions proceed under atmospheric conditions without drying of the solvent, and the co-product (4,6-dimethoxy-1, 3,5-triazin-2(1H)-one) arising from DMTMM after condensation can be readily removed by extraction, this method is a very practical one.

Synthesis and characterization of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride

Abstract 4-(4,6-Dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) was quantitatively synthesized by the coupling of 2-chloro-4,6-dimethoxy-1,3,5-triazine and N-methylmorpholine in THF, and fully characterized. Condensation of car☐ylic acids and amines by DMTMM proceeded effectively in THF to give the corresponding amides in good yield.

First chemo- and stereoselective reduction of imines using trichlorosilane activated with N-formylpyrrolidine derivatives

Abstract Trichlorosilane activated with N -formylpyrrolidine derivatives was found to be an effective reagent for reduction of imines to amines. The reagent showed much higher selectivity toward imino groups than carbonyl groups. The reduction of imines using trichlorosilane activated with optically active N -formylproline derivatives gave enantiomerically enriched amines in moderate optical yields (up to 66% ee).

Catalytic activation of trichlorosilane for efficient and stereoselective reduction of ketones

Abstract Some kinds of N-formyl cyclic amine derivatives were found to be effective activators for trichlorosilane to reduce ketones. Namely, a catalytic amount of these activators were sufficient to complete the reduction of ketones with trichlorosilane, and the reduction of ketones by trichlorosilane with optically active activators gave enantiomerically enriched sec-alcohols in some extent of optical yields (up to 51% ee).

A new convenient method for selective monobenzoylation of diols

Abstract A new facile method for monoacylation of diols has been developed. A variety of cyclic and acyclic diols, in particular 1,2-diols, was selectively monobenzoylated in good yields by their reaction with benzoyl chloride in the presence of a catalytic amount of dimethyltin dichloride and inorganic bases.

EFFECTIVE TRANSFORMATION OF ALDOXIMES TO NITRILES BY DEHYDRATION WITH 2-METHYLENE-1,3-DIOXEPANE IN THE PRESENCE OF A LEWIS ACID CATALYST

Abstract The dehydration of aldoximes with 2-methylene-1,3-dioxepane (MDO) proceeds smoothly in the presence of a catalytic amount of Lewis acid such as scandium(III) triflate to give corresponding nitriles in moderate to high yields under mild conditions.

Electro-organic chemistry. Part 93. Electro-organic transformation of aldehydes and ketones to α-hydroxylated acetals utilizing mediators and some synthetic uses of the products

Electro-oxidation of aldehydes (R1R2CHCHO) and ketones (R1R2HCOR3) in methanol containing iodide ion (I–) and KOH gave the corresponding α-hydroxylated acetals [R1R2C(OH)CH(OMe)2 and R1R2C(OH)C(OMe)2R3, respectively] in good yields. The first step of this oxidation is explained in terms of the attack of an anodically generated active iodine species ‘I+’ on enols of R1R2CHCHO and R1R2CHCOR3. α-Hydroxy acetals were useful starting materials as exemplified by reaction with aniline or methyl carbamates in the presence of Lewis acids to afford β-keto amine derivatives. The anodic oxidation of α-hydroxy acetals was also carried out.