Preparation of substituted enol derivatives from terminal alkynes and their synthetic utility

John R. DeBergh, Kathleen M. Spivey, Joseph M. Ready

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

Stereodefined enol derivatives of aldehydes are prepared from terminal alkynes. Specifically, terminal alkynes are known to undergo Cp2ZrCl2-catalyzed methylalumination. Here, we show that the resultant vinylalanes can be oxygenated with peroxyzinc species to generate trisubstituted enolates. Electrophilic trapping with carboxylic anydrides or silyl triflates yields trisubstituted enol esters or silanes, respectively. The tandem carbometalation/oxygenation tolerates free and protected alcohols, heterocycles, olefins, and nitriles. Stereodefined enol esters can undergo asymmetric dihydroxylation to yield optically active α-hydroxy aldehydes. Reduction with NaBH4 provides the diols of 1,1-disubstituted olefins in excellent ee. An application of this methodology to the enantioselective synthesis of the insect pheromone frontalin is presented. Finally, α-hydroxy aldehydes are shown to undergo homologation to a terminal alkyne, reductive amination, oxidation and olefination. Preliminary results indicate that tandem carbometalation/amination can be accomplished with azodicarboxylates. In this way, ene-hydrazines are formed in excellent yield.

Original languageEnglish (US)
Pages (from-to)7828-7829
Number of pages2
JournalJournal of the American Chemical Society
Volume130
Issue number25
DOIs
StatePublished - Jun 25 2008

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Alkynes
Aldehydes
Amination
Alkenes
Derivatives
Olefins
Esters
Hydrazines
Silanes
Nitriles
Oxygenation
Pheromones
Hydrazine
Insects
Alcohols
Oxidation

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

Preparation of substituted enol derivatives from terminal alkynes and their synthetic utility. / DeBergh, John R.; Spivey, Kathleen M.; Ready, Joseph M.

In: Journal of the American Chemical Society, Vol. 130, No. 25, 25.06.2008, p. 7828-7829.

Research output: Contribution to journalArticle

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