With annual production at >85 million tons/year, ethanol is the world's largest‐volume renewable small molecule carbon source, yet its use as a C2‐feedstock in enantioselective C−C coupling is unknown. Here, the first catalytic enantioselective C−C couplings of ethanol are demonstrated in reactions with structurally complex, nitrogen‐rich allylic acetates incorporating the top 10 N‐heterocycles found in FDA‐approved drugs.

Iridium-tol-BINAP-catalyzed reductive coupling of allylic acetates with oxetanones and azetidinones mediated by 2-propanol provides chiral α-stereogenic oxetanols and azetidinols. As illustrated in 50 examples, complex, nitrogen-rich substituents that incorporate the top 10 N-heterocycles found in Food and Drug Administration (FDA)-approved drugs are tolerated. In addition to 2-propanol-mediated reductive couplings, oxetanols and azetidinols may serve dually as reductant and ketone proelectrophiles in redox-neutral C–C couplings via hydrogen autotransfer, as demonstrated by the conversion of dihydro-1a and dihydro-1b to adducts 3a and 4a, respectively. The present method delivers hitherto inaccessible chiral oxetanols and azetidinols, which are important bioisosteres.

With annual production at >85 million tons/year, ethanol is the world's largest‐volume renewable small molecule carbon source, yet its use as a C2‐feedstock in enantioselective C−C coupling is unknown. Here, the first catalytic enantioselective C−C couplings of ethanol are demonstrated in reactions with structurally complex, nitrogen‐rich allylic acetates incorporating the top 10 N‐heterocycles found in FDA‐approved drugs.