The first catalytic enantioselective carbonyl (α-amino)allylations are described. Phthalimido-allene 1 and primary alcohols 2a−2z, 2a′−2c′ engage in hydrogen auto-transfer-mediated carbonyl reductive coupling by way of (α-amino)allyliridium−aldehyde pairs to form vicinal amino alcohols 3a−3z, 3a′−3c′ with high levels of regio-, anti-diastereo-, and enantioselectivity. Reaction progress kinetic analysis and isotopic labeling studies corroborate a catalytic cycle involving turnover-limiting alcohol dehydrogenation followed by rapid allene hydrometalation.

Side population (SP) cells can be used to identify putative cancer stem cells (CSC), but this technique is

The desulfonylation of β‐arylketosulfones has been achieved in good to excellent yields by using 3‐W blue LEDs light, 1 mol‐% organic dye eosin Y bis(tetrabutylammonium salt) as photocatalyst, and diisopropylethylamine as reducing agent. Mechanistic studies demonstrate that oxidative quenching of the excited eosin Y by β‐arylketosulfones plays a crucial role in the present photoredox catalytic cycle.

The direct and controlled activation of a C(sp(3) )H bond adjacent to an O atom is of particular synthetic value for the conventional derivatization of ethers or alcohols. In general, stoichiometric amounts of an oxidant are required to remove an electron and a hydrogen atom of the ether for subsequent transformations. Herein, we demonstrate that the activation of a CH bond next to an O atom could be achieved under oxidant-free conditions through photoredox-neutral catalysis. By using a commercial dyad photosensitizer (Acr(+) -Mes ClO4 (-) , 9-mesityl-10-methylacridinium perchlorate) and an easily available cobaloxime complex (Co(dmgBF2 )2 ⋅2 MeCN, dmg=dimethylglyoxime), the nucleophilic addition of β-keto esters to oxonium species, which is rarely observed in photocatalysis, leads to the corresponding coupling products and H2 in moderate to good yields under visible-light irradiation. Mechanistic studies suggest that both isochroman and the cobaloxime complex quench the electron-transfer state of this dyad photosensitizer and that benzylic CH bond cleavage is probably the rate-determining step of this cross-coupling hydrogen-evolution transformation.