نتایج جستجو برای: pyrroles
تعداد نتایج: 1881 فیلتر نتایج به سال:
Substituted pyrroles were prepared by a gold(I)-catalyzed acetylenic Schmidt reaction of homopropargyl azides. The reaction allows for regiospecific substitution at each position of the pyrrole ring under mild conditions. A mechanism in which azides serve as nucleophiles toward gold(I)-activated alkynes with subsequent gold(I)-aided expulsion of dinitrogen is proposed.
N-Sulfonyl-1,2,3-triazoles reacted with alkynes in the presence of a nickel(0)/phosphine catalyst to give substituted pyrroles, with the extrusion of molecular nitrogen; the triazole moiety isomerised to an alpha-imino diazo species, and the denitrogenative addition to nickel(0) was followed by the insertion of alkynes and reductive elimination.
The title compound, C(20)H(18)N(2)O(4), consists of a benzodiazepinedione system fused to a pyrrole system. The seven-membered ring adopts a boat-shaped conformation (with the methine C atom as the prow); the five-membered ring adopts an enveloped-shaped conformation (with the hydr-oxy-bearing C atom as the flap). In the crystal, the hydr-oxy group is hydrogen bonded to the carbonyl O atom of a...
Pyrrole derivatives 1a,b were used as precursors for the preparation of pyrrolo[2,3-d]pyrimidine derivatives 2a,b-7a,b. Also, the formation and structure of different pyrrolotriazolopyrimidine derivatives 8a,b-11a,b were discussed. Some of the prepared products showed potent antimicrobial activity.
We report the first results of ab initio multiconfigurational Ehrenfest simulations of pyrrole photodynamics. We note that, in addition to the two intersections of 1(1)A2 and 1(1)B1 states with the ground state 1(1)A1, which are known to be responsible for N-H bond fission, another intersection between the 1(2)A2 and 1(2)B1 states of the resulting molecular radical becomes important after the d...
TiCl2/nano-γ-Al2O3 as a new heterogeneous Lewis acid catalyst was synthesized and characterized by FE-SEM, XRD, FT-IR, EDS, XRF, BET and TGA. N-substituted pyrroles have been synthesized via Paal–Knorr reaction in the presence of TiCl2/nano-γ-Al2O3 at room temperature under solvent-free conditions.
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