Transition states for the carboalumination of alkenes and alkynes

Journal Article · Mon Sep 13 04:00:00 EDT 1999 · Organometallics

DOI:https://doi.org/10.1021/om990350y· OSTI ID:696630

Bundens, J W; Yudenfreund, J; Francl, M M ^[1]

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1. Bryn Mawr Coll., PA (United States). Dept. of Chemistry

Ab initio molecular orbital theory was used to characterize stationary points on the potential energy surface for the carboalumination of alkenes and alkynes. Activation energies and entropies of activation were calculated and found to be in good agreement with experimental values. A {pi}-complex between the alkyl aluminum and the substrate is a stable precursor to the transition structure. The transition structures are four-centered. Substituent effects on the transition structure geometries are small and predictable, suggesting that standard values for geometrical parameters for this and related reactions are reasonable. The anomalous relative reactivities of substrates can be explained by considering the reaction to essentially be a nucleophilic attack, rather than an electrophilic one.

• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 696630
• Journal Information: Organometallics, Journal Name: Organometallics Journal Issue: 19 Vol. 18; ISSN ORGND7; ISSN 0276-7333
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
ACTIVATION ENERGY
ALKENES
ALKYNES
ALUMINIUM COMPOUNDS
ENTROPY
MOLECULAR ORBITAL METHOD
MOLECULAR STRUCTURE