Published as part of the ISySyCat2019 Special Issue
Abstract
This account summarizes the development of new biheteroaromatic chiral bisphosphine oxides. 3,3′-Bithiophene-based phosphine oxides (BITIOPOs) have been successfully used as organocatalysts to promote Lewis base catalyzed, Lewis acid mediated stereoselective transformations. These highly electron-rich compounds, in combination with trichorosilyl derivatives (allyltrichlorosilane and silicon tetrachloride), generate hypervalent silicon species that act as chiral Lewis acids in highly diastereo- and enantioselective organic reactions. Several relevant examples related to these applications are discussed in detail.
1 Introduction
2 The BITIOPO Family
3 Enantioselective Opening of Epoxides
4 Enantioselective Allylation of Aldehydes
5 Stereoselective Direct (Double) Aldol-Type Reaction with Ketones
6 Stereoselective Direct Aldol-Type Reaction with Ester Derivatives
7 Conclusions
Key words
silicon hypercoordination - organocatalysis - Lewis bases - aldol reactions - stereoselective reactions - chiral phosphine oxides