|Budget Amount *help
¥7,200,000 (Direct Cost: ¥7,200,000)
Fiscal Year 1997: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1996: ¥5,000,000 (Direct Cost: ¥5,000,000)
New synthetic methods have been developed for the synthesis of various amino compounds based on the substitution reaction on the sp2 nitrogen atom of oximes.
1) Preparation of anilines by the direct amination of aromatic compounds
Electron rich aromatic compounds react with 1-indanone 0-methylsulfonyloxime in the presence of SnCl_4 and CF_3SO_3H,giving the corresponding imines. The imines thus formed are converted to aniline derivative by hydrolysis.
2) Preparation of dihydro pyrroles and tetrahydropyridines
Intramolecular substitution reaction of ketone 0-methylsulfonyloxime having active methylene group at the gamma- or delta-position proceeds in the presence of DBU to afford 3,4-dihydro-2H-pyrrole or 2,3,4,5-tetrahydropyridine, respectively.
3) Preparation of primary amines by coupling reactions of organometallics with 0-sulfonyloximes
Primary amines are synthesized by the coupling reaction between organometallic reagents and 0-sulfonyloximes. That is, in the presence of CuCN as a catalys
t, alkyl Grignard reagents react with 4,4'-bis (trifluoromethyl) benzophenone to give N-alkylimines, the hydrolysis of which yields primaray, secondary, and tertiary-alkylamines in high yield. By employing 3,3', 5,5'-tetrakis-(trifluoromethyl) benzophenone 0-p-toluenesulfonyloxime, the reaction with Grignard reagents proceeds without the copper catalyst, and anilines and alkylamines are obtained after hydrolysis of the resulted imines.
4) Preparation of the nitrogen containing heterocyclic compounds via alkylideneaminyl radicals
Intramolecular cyclization of m-hydroxyphenethylketone 0-2,4-dinitrophenyloximes proceeds by the treatment with NaH and DDQ,affording 8-hydroxyquinolines. The reaction of m-hydroxyphenethylketone 0-2,4-dinitrophenyloximes with NaH and NaBH_3CN gives 8-hydroxy-tetrahydroquinolines. It was found that these reactions proceed via an alkylideneaminyl radical intermediate generated by one electron transfer between the two phenyl groups. This electron transfer method for the generation of alkylideneaminyl radicals is further utilized for the synthesis of 3,4-dihydro-2H-pyrrole derivatives by the intramolecular radical addition to an olefinic moiety. Less