Journal article

Publication year: 2007

Pages: 779-790

Journal: Synthesis: Journal of Synthetic Organic Chemistry

Volume number: 2007

Issue number: 5

DOI Link: https://doi.org/10.1055/s-2007-965917

Publisher: Thieme Publishing / Georg Thieme Verlag

Abstract: 

This paper presents the first acid-free, organocatalytic tetrahydropyran and 2-methoxypropene protection of alcohols, phenols, and other ROH derivatives utilizing privileged N,N'-bis[3,5bis(trifluoromethyl)phenyl]thiourea and a polystyrene-bound analogue. The reactions are broadly applicably (also on preparative scale), in particular, to acid-sensitive substrates such as aldol products, hydroxy esters, acetals, silyl-protected alcohols, and cyanohydrins. The catalytic efficiency is truly remarkably with turnover numbers of 100,000 and turnover frequencies of up to 5 700 h(-1) at catalyst loadings down to 0.001 mol%. The computationally supported mechanistic interpretation emphasizes the hydrogen bond assisted heterolysis of the alcohol and concomitant preferential stabilization of the oxyanion hole in the transition state.

Harvard Citation style: Kotke, M. and Schreiner, P. (2007) Generally Applicable Organocatalytic Tetrahydropyranylation of Hydroxy Functionalities with Very Low Catalyst Loading, Synthesis: Journal of Synthetic Organic Chemistry, 2007(5), pp. 779-790. https://doi.org/10.1055/s-2007-965917

APA Citation style: Kotke, M., & Schreiner, P. (2007). Generally Applicable Organocatalytic Tetrahydropyranylation of Hydroxy Functionalities with Very Low Catalyst Loading. Synthesis: Journal of Synthetic Organic Chemistry. 2007(5), 779-790. https://doi.org/10.1055/s-2007-965917