71887-49-5Relevant academic research and scientific papers
Divergent Photocatalytic Reactions of α-Ketoesters under Triplet Sensitization and Photoredox Conditions
Dong, Xiao,Yoon, Tehshik P.,Zheng, Jian
, (2020)
The long-lived triplet excited states of transition metal photocatalysts can activate organic substrates via either energy- or electron-transfer pathways, and the rates of these processes can be influenced by rational tuning of the reaction conditions. The characteristic reactive intermediates generated, however, are distinct and can exhibit very different reactivity patterns. This mechanistic diversity available to photocatalytic reactions might thus offer an opportunity to engineer divergent reactions that give markedly different chemical outcomes under superficially similar conditions. Herein, we show that the photocatalytic reactions of benzoylformate esters with alkenes can be directed toward either Paternò-Büchi cycloadditions or allylic functionalization reactions under conditions favoring energy transfer or electron transfer, respectively. These studies provide a framework for designing other divergent photocatalytic methods that produce different sets of reaction outcomes under photoredox and triplet sensitization conditions.
Visible-Light-Enabled Paternò-Büchi Reaction via Triplet Energy Transfer for the Synthesis of Oxetanes
Rykaczewski, Katie A.,Schindler, Corinna S.
supporting information, p. 6516 - 6519 (2020/09/02)
One of the most efficient ways to synthesize oxetanes is the light-enabled [2 + 2] cycloaddition reaction of carbonyls and alkenes, referred to as the Paternò-Büchi reaction. The reaction conditions for this transformation typically require the use of hig
Synthesis, Reactivity, and Application as Chiral Auxiliaries of the Novel (3R)- and (3S)-4,5-Dihydro-3-hydroxy-4,4,5,5-tetramethyl-3-phenylfuran-2(3H)-ones in the Paterno-Buechi Reaction
Oppenlaender, Thomas,Schoenholzer, Peter
, p. 1792 - 1800 (2007/10/02)
Both enantiomers of the novel α-hydroxy-γ-lactone (+/-)-3 (4,5-dihydro-3-hydroxy-4,4,5,5-tetramethyl-3-phenyfuran-2(3H)-one) have been synthesized via hydrolysis of the oxetanes 2 derived from the photochemical cycloaddition of the ketones 1 and 2,3-dimethylbut-2-ene (Paterno-Buechi reaction) involving conventional separation of diastereisomers (Schemes 2 and 3).The absolute configuration of (R)- and (S)-3 and of the corresponding oxetane precursors could be assigned on the basis of an X-ray structural analysis of the (-)-(1S,4R)-camphanoyl derivative (3'S)-5 of (S)-3.O-acylation of (S)- and (+/-)-3 to yield a variety of derivatives ((3'S)- and (3'RS)-5 and (+/-)-7, (+/-)-8, (+/-)-9) was accomplished by deprotonation with BuLi at room temperature and subsequent quenching of the Li alcoholate with acyl chlorides or acid anhydrides, demonstrating the extraordinary chemical stability of 3.Additionally, the course of the temperature-dependent diastereoselective Paterno-Buechi reaction of 2,3-dimethylbut-2-ene to the benzoylformate (S)-7 ( = (S)-1d; obtained from (S)-3) was shown to proceed with 58 percent de at 60 deg C, leading to a decrease of enantiomeric purity in the hydrolysis product 3.
