Interaction of Dihydropyridines and Nucleophiles with Carbene Complexes of Chromium: Diastereo- and Enantioselective Synthesis of Polycyclic Butenolides

The interaction of N‐methyldihydropyridine with carbene complexes of chromium promotes their spontaneous homologation upon addition of a hydride to the carbene carbon and an insertion of CO. This is followed in the case of complexes tethered to a triple bond by cascade insertions of the triple bond...

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Bibliographic Details
Published in:	European journal of organic chemistry Vol. 2004; no. 11; pp. 2471 - 2502
Main Authors:	Rudler, Henri, Parlier, Andrée, Certal, Victor, Lastennet, Gabriel, Audouin, Max, Vaissermann, Jacqueline
Format:	Journal Article
Language:	English
Published:	Weinheim WILEY-VCH Verlag 01-06-2004 WILEY‐VCH Verlag
Subjects:	Butenolides Carbenes Chromium Dihydropyridines Nucleophiles
Online Access:	Get full text
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Summary:	The interaction of N‐methyldihydropyridine with carbene complexes of chromium promotes their spontaneous homologation upon addition of a hydride to the carbene carbon and an insertion of CO. This is followed in the case of complexes tethered to a triple bond by cascade insertions of the triple bond and of a CO ligand giving finally butenolides. The scope of the reaction has been established with its limitations, together with the stereochemical outcome, which is discussed. [5.5], [5.6], [5.7] bicyclic and tricyclic systems have been synthesised together with chiral butenolides starting from chiral carbene complexes. Most of the new structures have been assessed by X‐ray crystallography. This transformation was first extended to dihydronicotinamides, to chiral dihydropyridines such as dihydronicotines which led to the butenolides in an enantioselective way, and to other sources of hydrides. Second, a series of nucleophiles such as alkoxides, alkyllithium and alkylmagnesium compounds led also to polycyclic, substituted butenolides. Moreover, the final lactone enolates could be trapped with oxygen and gave unsaturated lactonols. The key point in all of these reactions is the formation of tetrahedral intermediates upon interaction of the nucleophiles with the carbene carbon. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Bibliography:	ArticleID:EJOC200400036 istex:E828FBA2BE10DBBA0CF4B71E7B23F261F613D215 ark:/67375/WNG-JL5BNWFL-J
ISSN:	1434-193X 1099-0690
DOI:	10.1002/ejoc.200400036