Selenium-catalyzed reductive carbonylation of nitrobenzene with amines as coreagents to give unsymmetric phenylureas

The reductive carbonylation of nitrobenzene catalyzed by selenium to yield unsymmetric phenylureas has been studied. When secondary amines were used as coreagents, a single product, PhNHCONR2, was formed; when primary amines were chosen as coreagents, mixed products, including RNHCONHR, RNHCONHPh and PhNHCONHPh, were obtained. (C) 1999 Elsevier Science Ltd. All rights reserved.

Highly efficient route to diselenides from the reactions of imines and selenium in the presence of carbon monoxide and water

Reactions of selenium with imines ((RRC)-C-1=NR2) of aldehydes and ketones in the presence of carbon monoxide, water and triethylamine lead to reductive selenation, on aerobic work-up, to afford symmetrical diselenides ((RRCHSe)-C-1)(2) in good to excellent yields. The proposed mechanism suggests that both in situ generated carbonyl selenide (SeCO) and hydrogen selenide (H2Se) are involved in the reaction.

Selenium-catalyzed reductive carbonylation of 2-nitrophenols to 2-benzoxazolones

2-Benzoxazolones or 2-benzimidazolones are synthesized in moderate to good yields in the presence of a base (KOH, NaOH, KOAc, NEt3, DBU) at atmospheric pressure or under a high pressure of CO by one-pot reductive carbonylation of 2-nitrophenols or 2-nitroanihne in the presence of selenium as catalyst. Besides the effect of base, the effects of solvent and temperature on the reaction were investigated at high or atmospheric pressure. Contrasting results were obtained for 2-benzoxazolones or 2-benzimidazolone at high and atmospheric pressures. Moreover, phase-transfer catalysis was exhibited. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005).