Chiral α-Stereogenic Oxetanols and Azetidinols Alcohol-Mediated Reductive Coupling of Allylic Acetates: Enantiotopic π-Facial Selection in Symmetric Ketone Addition.

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 -heterocycles found in 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 auto-transfer, as demonstrated by the conversion of - and - to adducts and , respectively.

Ethanol: Unlocking an Abundant Renewable C -Feedstock for Catalytic Enantioselective C-C Coupling.

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 C -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.

Mechanisms involved in adenosine triphosphate--induced platelet aggregation in whole blood.

Objective: Effects on platelet aggregation of adenosine triphosphate (ATP) released from damaged cells and from platelets undergoing exocytosis have not been clearly established. In this study we report on the effects of ATP on platelet aggregation in whole blood.

Methods And Results: Aggregation, measured using a platelet-counting technique, occurred in response to ATP and was maximal at 10 to 100 micromol/L.