Work

Computational Analysis of the Stereochemical Outcome in the Imidazolidinone-Catalyzed Enantioselective (4 + 3)-Cycloaddition Reaction

Year: 2014

Type: article

Abstract: Computations show why the catalytic, asymmetric (4 + 3)-cycloaddition reaction developed in the Harmata laboratories proceeds with facial selectivity opposite to that for models proposed for related catalyzed Diels-Alder reactions. Computations with M06-2X/6-311+G(d,p)//B3LYP/6-31G(d) show that iminium ions derived from MacMillan's chiral 2-tert-butyl-5-benzylimidazolidinone and siloxypentadienals undergo (4 + 3)-cycloadditions with furans preferentially on the more crowded face. Conformational reorganization of the benzyl group, to avoid intramolecular interaction with the silyl group, is responsible for differentiating the activation barriers of top- and bottom-face attack.

Source: The Journal of Organic Chemistry

DOI: 10.1021/jo501906m

Authors: Elizabeth H. Krenske, K. N. Houk, Michael Harmata

Institutions: The University of Queensland, University of California, Los Angeles, University of California System, University of Missouri

Language: English

Topic: Asymmetric Synthesis and Catalysis

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funders: National Science Foundation, National Institutes of Health, Australian Research Council, National Institute of General Medical Sciences