One-Pot Synthesis of N-Heterocyclic Compounds from Cyclopropenethione Derivatives

Abstract

The one-pot reaction of 2-tert-butylthio-3-phenylcyclopropenethione (1a) and its 3-(2-thienyl) derivative (1b) with lithium pyrrolidinide at -70 degrees C, followed by methylation with methyl iodide, gives 6-methylthio-5-phenyl-2,3-dihydro-1H-pyrrolizine (2a) and its 5-(2-thienyl) derivative (2b), respectively. The reaction of 2-tert-butylthio-3-(pyrrolidin-1-yl)cyclopropenethione (1c) with phenyllithium gives also 2a in a high yield under similar conditions, and the reactions of 1a with N-lithium salts of 3-pyrroline, hexamethyleneimine, indoline, and carbazole, piperidine-potassium tert-butoxide mixture, and phenyllithium give 6-methylthio-5-phenyl-3H-pyrrolizine (3), 2-methylthio-3-phenyl-6,7, 8,9-tetrahydro-5H-pyrrolo[1,2-a]azepine (5), 6-tert-butylthio-5-methylthio-4-phenyl-1,2-dihydro-6H-pyrrolo[3,2, 1-ij]quinoline (6), 4-tert-butylthio-5-methylthio-6-phenyl-4H-pyrido[3,2,1-jk]carbazole (7), 2-methylthio-3-phenyl-5,6,7,8-tetrahydroindolizine (4), and 1-tert-butylthio-2-methylthio-3-phenylindene (9), respectively. The structures of 2a and 3 were determined by X-ray analyses of their tricarbonylchromium complexes.

Cyclopropenylium Cations, Cyclopropenones, and HeteroanaloguesRecent Advances

“…The reaction of 2-tert-butylthio-3-phenylcyclopropenethione 396 with lithium pyrrolidinide, followed by methylation with methyl iodide, gave the 1Hpyrrolidine derivative 397 (eq 208). 350,351 Similar results have been observed for N-lithium salts of other cyclic amines. Interestingly, the reaction of 2-tertbutylthio-3-(pyrrolidin-1-yl)cyclopropenethione 398 with phenyllithium also gave 397 (eq 209).…”

“…Interestingly, the reaction of 2-tertbutylthio-3-(pyrrolidin-1-yl)cyclopropenethione 398 with phenyllithium also gave 397 (eq 209). 351 Earlier studies indicated that phenylmagnesium bromide attacks diphenylcyclopropenone at the carbonyl carbon (C-1), 36a while phenyllithium attacks the vinylic carbon (C-2). 352 In the latter reaction, a ringopening product, 1,2,2-triphenylpropionic acid, was obtained.…”

“…275 It was shown that 2-tert-butylthio-3-phenylcyclopropenethione 396 gives ring-opening products with phenyllithium at room temperature, 353 but the reaction at -70 °C, followed by treatment with MeI, proceeded through a pathway analogous to that shown in eq 208, to give 400 (eq 211). 351 A related thione, bis(tert-butylthio)cyclopropenethione, underwent substitution of a Bu t S group, rather than addition-ring opening, by pyrrolidine at room temperature or by phenyllithium at -80 °C (eq 212). 354 The Bu t S group in thione 396 was also substituted with pyrrolidine (eq 212).…”

“…It was shown that 2- tert -butylthio-3-phenylcyclopropenethione 396 gives ring-opening products with phenyllithium at room temperature, but the reaction at −70 °C, followed by treatment with MeI, proceeded through a pathway analogous to that shown in eq 208, to give 400 (eq 211) …”