Asymmetric intramolecular Cannizzaro reaction of anhydrous phenylglyoxal

Strongly enhanced acidity and activity of amorphous silica–alumina by formation of pentacoordinated AlV species

“…showed a PG conversion of 61.6 % and selectivity to EM of 98.7 % after a reaction time of 6 h. The enhancement of the Brønsted acidity of SA/Xx materials with increasing Al content up to 70 % significantly improved the PG conversion from 61.6 to 100 % under the same conditions and the selectivity of EM remained higher than 98.6 % for all samples. With SA/70x an EM yield of 99.8 % was achieved, which to our knowledge is the highest reported so far with solid acid catalysts[29,[46][47][48][49][50].…”

Advances in Stereoconvergent Catalysis from 2005 to 2015: Transition-Metal-Mediated Stereoablative Reactions, Dynamic Kinetic Resolutions, and Dynamic Kinetic Asymmetric Transformations

“… A variety of aryl and alkyl glyoxal hydrates reacted smoothly with alcohols to produce α-hydroxyesters with excellent ee. The mechanism for stereoinduction in asymmetric Cannizzaro reactions is subject to an ongoing debate, and where one proposal qualifies as a DyKAT (path A) , another favors an enantioselective addition route (path B) . It is postulated that, under the reaction conditions, substrate 283 dehydrates to form glyoxal 285 that can reversibly form racemic hemiacetals 285 .…”

Chiral N,N′-dioxide–FeCl3 complex-catalyzed asymmetric intramolecular Cannizzaro reaction

“…Such results were different from those with Tang's TOX-Cu(OTf) 2 catalytic system. 9 It is reasonable to speculate that the dynamic kinetic resolution of the hemiacetals might dominate in this case, 7,8 although the enantioselective addition pathway could not be completely excluded.…”