New Insights into the Stereoselectivity of the Aryl Zinc Addition to Aldehydes
- 14 January 2005
- journal article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 127 (5) , 1548-1552
- https://doi.org/10.1021/ja046254s
Abstract
The addition of Ph2Zn to aldehydes has been investigated by DFT calculations. The experimentally observed increase in enantioselectivity upon addition of Et2Zn to the reaction mixture is rationalized from calculations of all isomeric transition states. Spectator ethyl groups in the transition state do not lower the intrinsic activation barrier, but instead increase it. In the presence of a bulky ligand, the inherently preferred all-phenyl transition state is selectively disfavored. The paths with less sterically demanding spectator ethyl groups will experience a more drastic ligand acceleration, and thus the influence of the ligand would be expected to be stronger in the presence of Et2Zn, in agreement with experimental observations.Keywords
This publication has 24 references indexed in Scilit:
- 2-Piperidino-1,1,2-triphenylethanol: A Highly Effective Catalyst for the Enantioselective Arylation of AldehydesThe Journal of Organic Chemistry, 2004
- Quantum Mechanical Models Correlating Structure with Selectivity: Predicting the Enantioselectivity of β-Amino Alcohol Catalysts in Aldehyde AlkylationJournal of the American Chemical Society, 2003
- Modeling the Stereoselectivity of the β-Amino Alcohol-Promoted Addition of Dialkylzinc to AldehydesJournal of the American Chemical Society, 2003
- A Synthetic Azinomycin Analogue with Demonstrated DNA Cross-Linking Activity: Insights into the Mechanism of Action of this Class of Antitumor AgentPublished by Wiley ,2000
- Asymmetric Addition of Dimethylzinc to Benzaldehyde Catalyzed by (2S)-3-exo-(Dimethylamino)isobornenol. A Theoretical Study on the Origin of EnantioselectionOrganometallics, 1998
- Origin of Enantioselectivities in Chiral β-Amino Alcohol Catalyzed Asymmetric Additions of Organozinc Reagents to Benzaldehyde: PM3 Transition State ModelingThe Journal of Organic Chemistry, 1998
- Coordinational behavior of solvent-free diorganylzinc compounds: the remarkable x-ray structure of dimeric diphenylzincOrganometallics, 1990
- The Interplay Between Chemistry and Biology in the Design of Enzymatic CatalystsScience, 1988
- New steroids by Simmons-Smith methylenation and subsequent rearrangementThe Journal of Organic Chemistry, 1987
- New 1,4-dihydropyridine derivatives with potent and long-lasting hypotensive effect.CHEMICAL & PHARMACEUTICAL BULLETIN, 1985