Copper-Catalyzed Vinylation of Hydrazides. A Regioselective Entry to Highly Substituted Pyrroles
摘要:
A modular route to highly substituted pyrroles has been developed. This transformation consists of two sequential copper-catalyzed vinylations of bis-Boc-hydrazine followed by thermal rearrangement/cyclization. A wide variety of functionalized pyrroles can be prepared in a selective manner from simple and easily accessible precursors.
The synthesis of pyrroles and oxazoles based on gold α-imino carbene complexes
作者:Nicole S. Y. Loy、Subin Choi、Sunggak Kim、Cheol-Min Park
DOI:10.1039/c6cc01742h
日期:——
Cationic gold complexes of [small alpha]-oximimino carbenes have been identified to react with nucleophiles with attenuated reactivity including enol ethers and nitriles. These findings allowed us to develop highly efficient synthesis...
Facile and one-pot synthetic route of poly-substituted pyrroles and 4-oxo-4,5,6,7-tetrahydroindoles is established, which consists of three steps: (1) palladium-catalyzed oxidation of hydroxy-enamines by using tetrakis(triphenylphosphine)palladium and mesityl bromide oxidation system, (2) intramolecular cyclization, and (3) dehydration.
A Powerful New Strategy for Diversity-Oriented Synthesis of Pyrroles from Donor−Acceptor Cyclopropanes and Nitriles
作者:Ming Yu、Brian L. Pagenkopf
DOI:10.1021/ol036180+
日期:2003.12.1
Lewisacid activated donor-acceptor cyclopropanes react with aliphatic, aromatic, and alpha,beta-unsaturated nitriles in a novel cascade [3 + 2] dipolarcycloaddition, dehydration, and tautomerization sequence to afford pyrroles in moderate to excellent overall yield. This cost-effective and regiospecific method is ideally suited for the preparation of combinatorial libraries. [reaction: see text]
The synthesis and chemistry of azolenines. Part 18. Preparation of 3-ethoxycarbonyl-3-pyrroles the paal-knorr reaction, and sigmatropic rearrangements involving competitive ester migrations to c-2, c-4 and n.
作者:Chiu Pak-Kan、Sannes Michael P.
DOI:10.1016/s0040-4020(01)81514-3
日期:1990.1
N-esters (13) of 1H-pyrroles via competitive [1,5]sigmatropic rearrangements. Isolable intermediate 2H-pyrrole-2-carboxylic esters (l2) are converted similarly into the same products, under the same conditions. Detection of 3H-pyrroles (4) as intermediates in the latter reaction demonstrates for the first time the reversibility of the thermal 2H-pyrrole to 3H-pyrrole interconversion.
Reaction of Allenyl Esters with Sodium Azide: An Efficient Synthesis of <i>E</i>-Vinyl Azides and Polysubstituted Pyrroles
作者:Xian Huang、Ruwei Shen、Tiexin Zhang
DOI:10.1021/jo062376m
日期:2007.2.1
The nucleophilic addition of sodium azide to 1,2-allenyl esters can generate vinyl azides in excellent yields with excellent regio- and stereoselectivities. Moreover, pyrroles are synthesized using 1-allyllic 1,2-allenyl esters as substrates in t-BuOH at 65 °C. The sequential reaction for pyrroles is developed on the basis of a novel domino process involving nucleophilic addition, cycloaddition, denitrogenation