Condensation Reactions of a Nitrodienamine with Grignard and Organocopper Reagents Prepared from Indole Derivatives

Condensation reactions of a nitrodienamine (1) with Grignard and organocopper reagents prepared from indole derivatives were investigated.Indolyl Grignard reagents were prepared from 4-bromoindole (3a).5-bromoindole (3b), 6-bromoindole (3c).and 5-nitroindole (3d) using methylmagnesium bromide.Indolyl organcapper reagents were prepared from indole (3e).2-methylidole (3 f), and 3-methylindole (3 g) using dimethylcopperlithium.We are interested in the reactivities of the nitrodienamines containing enamine, olefiic, and nitro attracting moiety as well as aminodienyl esters and aminoacrylates synthons, because of their electronic "push-pull" character which can lead to interesting cycloaddition reactions.'-'In a previous study,6 we reported a synthesis of nitrodienamine, 1-(N,N-dimethylamino)-4-nim-1.3-butadiene(1).some cycloadditions of 1 with a,P-unsaturated carbonyl compounds and quinones, and condensation reactions of 1 with Grignard reagents prepared from indoles and carbazole using arylmagnesium halide and alkylmagnesium halide.In this paper we describe the condensation reactions of 1 with Grignard and organocopper reagents to afford the corresponding products(5).(6).and (7).Indolyl Grignard reagents were prepared from Cbromo-indoleOa), 5-bromoindole(3b), 6-bmmoindole(3c), and 5-nimindole(3d) using methylmagnesium bromide.Indolyl organcapper reagents were prepared from indole(3e), 2-methylidole(3f), and 3methylindole(3 g) using dimethylcopperlithium. .