Highly Regio- and Enantioselective Copper-Catalyzed Reductive Hydroxymethylation of Styrenes and 1,3-Dienes with CO₂

Herein, we report a highly regio- and enantioselective copper-catalyzed reductive hydroxymethylation of styrenes and 1,3-dienes with 1 atm of CO₂. Diverse important chiral homobenzylic alcohols were readily prepared from styrenes. Moreover, a variety of 1,3-dienes also were converted to chiral homoallylic alcohols with high yields and excellent regio-, enantio-, and Z/E-selectivities. The utility of this transformation was demonstrated by a broad range of styrenes and 1,3-dienes, facile product modification, and synthesis of bioactive compounds (R)-(-)-curcumene and (S)-(+)-ibuprofen. Mechanistic studies demonstrated the carboxylation of phenylethylcopper complexes with CO₂ as one key step.