Catalyst-controlled torquoselectivity switch in the 4π ring-opening reaction of 2-amino-2-azetines giving β-substituted α,β-unsaturated amidines

Naoya Shindoh; Kazuo Kitaura; Yoshiji Takemoto; Kiyosei Takasu

doi:10.1021/ja202576e

Catalyst-controlled torquoselectivity switch in the 4π ring-opening reaction of 2-amino-2-azetines giving β-substituted α,β-unsaturated amidines

J Am Chem Soc. 2011 Jun 8;133(22):8470-3. doi: 10.1021/ja202576e. Epub 2011 May 16.

Authors

Naoya Shindoh¹, Kazuo Kitaura, Yoshiji Takemoto, Kiyosei Takasu

Affiliation

¹ Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8571, Japan.

PMID: 21557577
DOI: 10.1021/ja202576e

Abstract

The torquoselectivity of the 4π electrocyclic ring-opening reaction of 2-azetines can be controlled by the Brønsted acidity of the catalyst and the polarity of the solvent. DFT calculations provided insight into the mechanism of this remarkable switch. Anti and syn stereoisomers of α,β-unsaturated amidines were selectively synthesized from ynamides and aldimines in the presence of Tf(2)NH and CSA, respectively.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Amidines / chemistry*
Amines / chemistry*
Azetines / chemistry*
Carbamates / chemistry
Catalysis
Magnetic Resonance Spectroscopy
Molecular Structure
Stereoisomerism
Thermodynamics

Substances

Amidines
Amines
Azetines
Carbamates