نتایج جستجو برای: multisubstituted pyrroles
تعداد نتایج: 2001 فیلتر نتایج به سال:
Described herein is an environmentally benign method for the synthesis of multisubstituted 3-alkoxylated-2-oxindoles 3 via direct alkoxylation of 3-halooxindoles 1. A wide variety of such multisubstituted 3-alkoxylated-2-oxindole scaffolds were smoothly obtained in good yields (up to 94%) by heating in an oil bath at 35 °C for 24 h. A particularly valuable feature of this method was the develop...
Indole synthesis by a gold(I)-catalyzed intermolecular formal [4+2] reaction between 1,3-diynes and pyrroles has been developed. This reaction involves the hydroarylation of 1,3-diynes with pyrroles followed by an intramolecular hydroarylation to give the 4,7-disubstituted indoles. This reaction can also be applied to the synthesis of carbazoles when indoles are used as the nucleophiles instead...
Divergent syntheses of indolizines and 2,4-disubstituted pyrroles by the silver-catalyzed cyclization of 2-pyridyl alkynyl carbinols with isocyanides are reported. These methods provide an effective route to highly functionalized indolizines and 2,4-disubstituted pyrroles in good to excellent yields. The 2,4-disubstituted pyrroles are synthesized by an unprecedented regioselective [3+2] cycload...
A three-component reaction has been developed that allows the regioselective synthesis of thieno[2,3-c]pyrroles. The reaction is based on the ability of 2-acetyl-3-thiophenecarboxaldehyde to react with amine and thiol nucleophiles to produce the corresponding tri-substituted thieno[2,3-c]pyrroles, with water as the only by-product. The developed reaction expands the range of synthetically acces...
A new route to carboranylated pyrroles and porphyrins is reported which involves the Suzuki coupling of readily available bromo- and boronic acid-pyrroles and bromoporphyrins with functionalized carboranes; the X-ray structures of two targeted products are presented and discussed.
2-Trifluoromethyl-5-(arylsulfonyl)methyl pyrroles and 2-trifluoromethyl-4-(arylsulfonyl)methyl pyrroles were selectively synthesized from trifluoromethyl-substituted 3-aza-1,5-enynes via a cyclization/sulfonyl group migration cascade catalyzed by AgOOCCF3 and CsOPiv, respectively. Alkylvinyl-substituted pyrroles were generated from seven-atom skeleton 3-aza-1,5-enynes via aryl sulfinic acid eli...
BACKGROUND The classical Paal-Knorr reaction is one of the simplest and most economical methods for the synthesis of biologically important and pharmacologically useful pyrrole derivatives. RESULTS Polystyrenesulfonate-catalyzed simple synthesis of substituted pyrroles following Paal-Knorr reaction has been accomplished with an excellent yield in aqueous solution. This method also produces py...
One-pot synthesis of substituted pyrroles by a cascade reaction of azides with Morita-Baylis-Hillman acetates of acetylenic aldehydes is described and the reaction is efficiently mediated by triphenyl phosphine at room temperature. Sodium azide is successfully used to provide N-unsubstituted pyrroles, while alkyl azides afforded the corresponding N-alkylated pyrroles through a sequence of allyl...
Catalytic Stereospecific Allyl–Allyl Cross-Coupling of Internal Allyl Electrophiles with AllylB(pin)
Application of internal electrophiles in catalytic stereospecific allyl-allyl cross-coupling enable the rapid construction of multisubstituted 1,5-dienes, including those with all carbon quaternary centers. Compounds with minimal steric differentiation can be synthesized with high enantiomeric excess.
The N-heterocyclic carbene-catalyzed [4 + 2] cyclization of ketenes and 3-aroylcoumarins has been developed to give the corresponding dihydrocoumarin-fused multisubstituted dihydropyranones in high yield with good diastereoselectivity and high enantioselectivity.
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