A Complementary Toolbox of Iterative Methods for the Stereo­selective Synthesis of Heteroatom-Rich Motives from C1-Building Blocks

Abstract The ability to assemble organic molecules one carbon atom at a time has been a long-held dream for chemists. Modern boronate homologations with chiral carbenoids allow for the assembly-line synthesis of long chiral alkyl chains with excellent control over individual stereocenters. Nevertheless, heteroatom rich motives present a serious synthetic challenge to this approach. Interestingly, older methods based on substrate-controlled homologations of chiral boronic esters or umpolung of a carbonyl nucleophile can offer complementary solutions. A combination of these approaches might thus extend the range of possible targets currently within grasp of a C 1 -based synthesis. Link to video abstract: https://www.youtube.com/watch?v=PH_HBrqQwtg . 1 Introduction 2 Substrate Control: Stereoselective Addition of d 1 -Reagents to Aldehydes­ 3 Stereocontrol by Chiral Auxiliary/Director: The Matteson Boronate Homologation 4 Reagent Control: Moving Chiral Information to the Carbenoid 5 Conclusions and Outlook