CaltechAUTHORS
  A Caltech Library Service

Selective Methylative Homologation: An Alternate Route to Alkane Upgrading

Bercaw, John E. and Hazari, Nilay and Labinger, Jay A. and Scott, Valerie J. and Sunley, Glenn J. (2008) Selective Methylative Homologation: An Alternate Route to Alkane Upgrading. Journal of the American Chemical Society, 130 (36). pp. 11988-11995. ISSN 0002-7863. https://resolver.caltech.edu/CaltechAUTHORS:BERjacs08

[img]
Preview
Cover Image - Cover Image
See Usage Policy.

1131b
[img] PDF - Supplemental Material
See Usage Policy.

2764b
[img] MS Excel - Supplemental Material
See Usage Policy.

2763b

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:BERjacs08

Abstract

InI3 catalyzes the reaction of branched alkanes with methanol to produce heavier and more highly branched alkanes, which are more valuable fuels. The reaction of 2,3-dimethylbutane with methanol in the presence of InI3 at 180−200 °C affords the maximally branched C7 alkane, 2,2,3-trimethylbutane (triptane). With the addition of catalytic amounts of adamantane the selectivity of this transformation can be increased up to 60%. The lighter branched alkanes isobutane and isopentane also react with methanol to generate triptane, while 2-methylpentane is converted into 2,3-dimethylpentane and other more highly branched species. Observations implicate a chain mechanism in which InI3 activates branched alkanes to produce tertiary carbocations which are in equilibrium with olefins. The latter react with a methylating species generated from methanol and InI3 to give the next-higher carbocation, which accepts a hydride from the starting alkane to form the homologated alkane and regenerate the original carbocation. Adamantane functions as a hydride transfer agent and thus helps to minimize competing side reactions, such as isomerization and cracking, that are detrimental to selectivity.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1021/ja803029sDOIArticle
ORCID:
AuthorORCID
Labinger, Jay A.0000-0002-1942-9232
Additional Information:© 2008 American Chemical Society. Received April 24, 2008. Web Release Date: August 13, 2008. We thank Professor Enrique Iglesia for useful discussions. This work was supported by BP through the MC^2 program. Supporting Information Available. A complete listing of experimental results (in Excel format), along with an explanatory guide to the Excel tables and details of a labeling experiment. This material is available free of charge via the Internet at http://pubs.acs.org.
Funders:
Funding AgencyGrant Number
BP MC2 programUNSPECIFIED
Issue or Number:36
Record Number:CaltechAUTHORS:BERjacs08
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:BERjacs08
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:11803
Collection:CaltechAUTHORS
Deposited By: Archive Administrator
Deposited On:30 Sep 2008 02:50
Last Modified:03 Oct 2019 00:22

Repository Staff Only: item control page