Organometallic Reagents and Regiodivergent RRM

Chiral organometaUic reagents offer the broadest range of possibilities for enantiodivergent reactions. The oldest and most extensively studied cases involve displacement reactions of allylic C—O bonds to give regioisomeric products under 

Given the wide variety of transition metal-catalysed reactions, there are many possibilities for divergent RRM involving organometallic intermediates. The examples summarized in the following sections illustrate several mechanistically distinct options for achieving enantiodivergent behaviour, and in some cases, also demonstrate remarkably different behaviour by substrate enantiomers upon exposure to a chiral catalyst. 

Davies and Venkataramani [47a] have used similar catalysts to generate chiral rhodium carbenoids from diazoesters under KR conditions. Among many examples of enantioselective C—H insertions, one case of enantiodivergent RRM was documented using individual enantiomers as substrates. However, the reactions with racemic substrates were limited to simple KR conditions (excess racemic substrate). Application of this stereodivergent Rh-catalysed cyclopropanation towards 

Several unusual examples of transition metal-catalysed divergent cyclizations have been reported. A regiodivergent rhodium-catalysed tandem conjugate 

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