Alkane desaturation by concerted double hydrogen atom transfer to benzyne

Dawen Niu, Patrick H. Willoughby, Brian P. Woods, Beeraiah Baire, Thomas R. Hoye

Research output: Contribution to journalArticlepeer-review

95 Scopus citations

Abstract

The removal of two vicinal hydrogen atoms from an alkane to produce an alkene is a challenge for synthetic chemists. In nature, desaturases and acetylenases are adept at achieving this essential oxidative functionalization reaction, for example during the biosynthesis of unsaturated fatty acids, eicosanoids, gibberellins and carotenoids. Alkane-to-alkene conversion almost always involves one or more chemical intermediates in a multistep reaction pathway; these may be either isolable species (such as alcohols or alkyl halides) or reactive intermediates (such as carbocations, alkyl radicals, or σ-alkyl-metal species). Here we report a desaturation reaction of simple, unactivated alkanes that is mechanistically unique. We show that benzynes are capable of the concerted removal of two vicinal hydrogen atoms from a hydrocarbon. The discovery of this exothermic, net redox process was enabled by the simple thermal generation of reactive benzyne intermediates through the hexadehydro-Diels-Alder cycloisomerization reaction of triyne substrates. We are not aware of any single-step, bimolecular reaction in which two hydrogen atoms are simultaneously transferred from a saturated alkane. Computational studies indicate a preferred geometry with eclipsed vicinal C-H bonds in the alkane donor.

Original languageEnglish (US)
Pages (from-to)531-534
Number of pages4
JournalNature
Volume501
Issue number7468
DOIs
StatePublished - 2013

Bibliographical note

Funding Information:
Acknowledgements We thank C. J. Cramer for helpful discussions about the computational studies. D.N. and P.H.W. thank the University of Minnesota Graduate School Doctoral Dissertation Fellowship and National Science Foundation Graduate Research Fellowship program, respectively. Financial support from the National Institute of General Medical Sciences (GM65597) and the National Cancer Institute (CA76497) of the US Department of Health and Human Services is acknowledged. Portions of this work were performed with hardware and software resources available through the University of Minnesota Supercomputing Institute (MSI).

Fingerprint Dive into the research topics of 'Alkane desaturation by concerted double hydrogen atom transfer to benzyne'. Together they form a unique fingerprint.

Cite this