Link to the University of Pittsburgh Homepage
Link to the University Library System Homepage Link to the Contact Us Form

Computational insight concerning catalytic decision points of the transition metal catalyzed [2 + 2 + 1] cyclocarbonylation reaction of allenes

Bayden, AS and Brummond, KM and Jordan, KD (2006) Computational insight concerning catalytic decision points of the transition metal catalyzed [2 + 2 + 1] cyclocarbonylation reaction of allenes. Organometallics, 25 (22). 5204 - 5206. ISSN 0276-7333

[img] Plain Text (licence)
Available under License : See the attached license file.

Download (1kB)

Abstract

Rhodium- and molybdenum-catalyzed allenic [2 + 2 + 1] cycloaddition reactions give 4-alkylidene and α-alkylidene cylopentenones, respectively. The selective reaction of one double bond of the allene over another is controlled by the transition metal and not the substrate structure. Calculations were performed to explain this unique control element using the B3LYP functional as implemented in Gaussian 03. The 6-31G(d) basis set was applied to all elements except rhodium, which is described with the LANL2 effective core potential and the LANL2DZ basis set. The product-determining step for both reaction pathways is oxidative addition of the metal to the alkynyl allene to form the corresponding metallocycles B and B'. The calculations strongly suggest that geometric constraints imposed by the metal in the transition state are the key controlling factor of the double-bond selectivity. The transition state structure of rhodium-catalyzed oxidative addition has a distorted square planar geometry that affords a lower transition state energy when coordinated to the distal double bond of the allene. In turn, the distorted trigonal bipyramidal geometry of molybdenum in the transition state structure imposes conformational constraints upon binding to the distal double bond on the allene and thus leads to the energetically preferred complexation and reaction with the proximal double bond. © 2006 American Chemical Society.


Share

Citation/Export:
Social Networking:
Share |

Details

Item Type: Article
Status: Published
Creators/Authors:
CreatorsEmailPitt UsernameORCID
Bayden, AS
Brummond, KMkbrummon@pitt.eduKBRUMMON
Jordan, KDjordan@pitt.eduJORDAN
Date: 23 October 2006
Date Type: Publication
Journal or Publication Title: Organometallics
Volume: 25
Number: 22
Page Range: 5204 - 5206
DOI or Unique Handle: 10.1021/om0607503
Schools and Programs: Dietrich School of Arts and Sciences > Chemistry
Refereed: Yes
ISSN: 0276-7333
Date Deposited: 03 May 2013 14:45
Last Modified: 02 Feb 2019 15:56
URI: http://d-scholarship.pitt.edu/id/eprint/18239

Metrics

Monthly Views for the past 3 years

Plum Analytics

Altmetric.com


Actions (login required)

View Item View Item