Synthesis of nitrogen heterocycles

A silver-catalyzed cascade reaction of simple anilines and alkynes generates 

On the other hand, indoline, a secondary amine, reacts with alkynes in the presence of a Au(I) phosphine complex as catalyst [38]. Treatment of indoline with phenylacetylene using 5 mol % Au(I) phosphine complex/AgOTf in MeCN gives 

2- dihydroquinoline in 91% yield under microwave irradiation. This reaction can be carried out using MeNOa as solvent and Au(I) catalyst/AgSbFe at room temperature 

A total synthesis of 6-deoxyclitoriacetal, a cyctotoxic natural product, was achieved using platinum-catalyzed intramolecular hydroarylation of a propargyl aryl 

A hydroarylation reaction is an atom-economical, efiticient process with 100% atom efficiency. Since the hydroarylation is a simple and intelligible reaction in which both an aryl group and a hydrogen atom add to a multiple bond, it is easy to grasp its ability for use in various synthetic reactions. In addition, since intramolecular hydroarylation is more efficient than the corresponding intermolecular reaction in many cases, it becomes methodologically promising for the synthesis of cyclic compounds such 

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Nesi R., Giorni D. and Turchi S. Synthesis of Nitrogen Heterocycles hy Hetero Diels-Alder Reactions in Seminars in Organic Synthesis. 24th Summer Sch A. Corbella 1999 225, Ed. Trombini, Pb. Soc. Chim. Ital. 

Waldmann H. Amino Add Esters Versatile Chiral Auxiliary Groups for the Asymmetric Synthesis of Nitrogen Heterocycles Synlett 1995 133-141... 

Norrish Type II photocyclizations have been employed in many instances in the synthesis of nitrogen heterocycles. Type II cyclizations are the result of an intramolecular hydrogen abstraction by an excited carbonyl group followed by cyclization of the resulting biradical. Hydrogen abstraction from the y-carbon atom is normally preferred. The introduction of a nitrogen atom... 

In contrast to the palladium-catalyzed reactions, little attention has been paid to other transition-metal catalysts. Recently some efficient reactions using copper(i or 11), gold(m), platinum(n), and tungsten(O) have been developed for the synthesis of nitrogen-heterocycles. The copper-catalyzed cyclizations of 2-alkynylaniline derivatives into... 

Gwilherm Evano was born in 1977 in Paris he studied chemistry at the Ecole Normale Superieure in Paris and received his Ph.D. from Universite Pierre et Marie Curie in 2002 under the supervision of Professors Francois Couty and Claude Agami. After postdoctoral study with Professor James S. Panek at Boston University, he became assistant professor at the University of Versailles in 2004. His research interests concern the field of asymmetric synthesis of nitrogen heterocycles as well as their reactivity and the total synthesis of natural products. 

At that time, as now, the enantiomers of many chiral amines were obtained as natural products or by synthesis from naturally occurring amines, a-amino acids and alkaloids, while others were only prepared by introduction of an amino group by appropriate reactions into substances from the chiral pool carbohydrates, hydroxy acids, terpenes and alkaloids. In this connection, a recent review10 outlines the preparation of chiral aziridines from enantiomerically pure starting materials from natural or synthetic sources and the use of these aziridines in stereoselective transformations. Another report11 gives the use of the enantiomers of the a-amino acid esters for the asymmetric synthesis of nitrogen heterocyclic compounds. 

Two independent papers have reported the synthesis of nitrogen-heterocycle complexes of the type [RhCl3(py-X)3] (py-X = 3-Etpy, 3-CNpy, 4-Etpy, or 4-CNpy) and rr(ans-[RhY2L4] (Y = Cl or Br L = several substituted pyridines, isoquinoline, pyrimidine, pyrazole, thiazole, and substituted imidazoles). All the compounds were prepared catalytically by boiling RhCl3.3H20 with ethanolic solutions of L. It is interesting that 2-substituted... 

B-2005MI65 R. Pedrosa, C. Andres, and J. Nieto in New Methods for the Asymmetric Synthesis of Nitrogen Heterocycles ,... 

Mori has independently developed a procedure for the cyclization/stannylsilylation of enynes similar to that developed by Lautens. As an example of Mori s procedure, reaction of dimethyl allylpropargylmalonate with trimethylsilyltributylstannane catalyzed by Pearlman s catalyst [Pd(OH)2/C] in THF at room temperature for 20 h formed cyclopentane 94 [X = C(C02Me)2] in 90% yield (Equation (61)). The transformation was compatible with a number of functional groups, tolerated limited substitution of the G=C bond, and was applicable to the synthesis of nitrogen heterocycles. In a notable example, reaction of the benzhydryl-protected allylpropargylamine 95 with MesSiSnBus catalyzed by Pd(OH)2/C formed the bis(functionalized) octahydroindole 96 in 66% yield as a single diastereomer (Equation (62)). 

SYNTHESIS OF NITROGEN HETEROCYCLES FROM SACCHARIDE DERIVATIVES... 

Larock, R. C. Babu, S. Synthesis of Nitrogen Heterocycles via Palladium-Catalysed Intramolecular Cyclisation, Tetrahedron Lett. 1987, 28, 5291-5294. 

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