Indium- and zinc-catalyzed enantioselective amide propargylation of aldehydes with stannylated allenyl amides

Photoredox cobalt-catalyzed regio-, diastereo- and enantioselective propargylation of aldehydes via propargyl radicals

Catalytic enantioselective introduction of a propargyl group constitutes one of the most important carbon-carbon forming reactions, as it is versatile to be transformed into diverse functional groups and frequently used in the synthesis of natural products and biologically active molecules. Stereoconvergent transformations of racemic propargyl precursors to a single enantiomer of products via propargyl radicals represent a powerful strategy and provide new reactivity. However, only few Cu- or Ni-catalyzed protocols have been developed with limited reaction modes. Herein, a photoredox/cobalt-catalyzed regio-, diastereo- and enantioselective propargyl addition to aldehydes via propargyl radicals is presented, enabling construction of a broad scope of homopropargyl alcohols that are otherwise difficult to access in high efficiency and stereoselectivity from racemic propargyl carbonates. Mechanistic studies and DFT calculations provided evidence for the involvement of propargyl radicals, the origin of the stereoconvergent process and the stereochemical models.

Enantioselective Indium-Catalyzed Transformations

This review updates the field of enantioselective indium-catalyzed transformations of all types since 2012. It shows that asymmetric indium catalysis, that suits the growing demand for greener processes, offers a real opportunity to replace toxic metals in the near future.

1 Introduction

2 Allylations, Propargylations, and Allenylations of Carbonyl Compounds and Derivatives

2.1 Allylations

2.2 Propargylations and Allenylations

3 Cycloadditions

3.1 Hetero-Diels–Alder Cycloadditions

3.2 1,3-Dipolar Cycloadditions

4 Miscellaneous Reactions

5 Domino and Tandem Reactions

6 Conclusion