1499-21-4Relevant articles and documents
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Sosnovsky,Rawlinson
, p. 2325,2328 (1968)
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Vicentini,Braga
, p. 2959,2961 (1971)
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Hunt,Saunders
, p. 2413 (1957)
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Enantiodivergent Kinetic Resolution of 1,1′-Biaryl-2,2′-Diols and Amino Alcohols by Dipeptide-Phosphonium Salt Catalysis Inspired by the Atherton–Todd Reaction
Chen, Yuan,Fang, Siqiang,Pan, Jianke,Ren, Xiaoyu,Tan, Jian-Ping,Wang, Tianli,Zhang, Hongkui
supporting information, p. 14921 - 14930 (2021/05/10)
A highly enantiodivergent organocatalytic method is disclosed for the synthesis of atropisomeric biaryls via kinetic resolution inspired by a dipeptide-phosphonium salt-catalyzed Atherton–Todd (A-T) reaction. This flexible approach led to both R- and S-enantiomers by fine-tuning of bifunctional phosphonium with excellent selectivity factors (s) of up to 1057 and 525, respectively. The potential of newly synthesized O-phosphorylated biaryl diols was illustrated by the synthesis of axially chiral organophosphorus compounds. Mechanistic investigations suggest that the bifunctional phosphonium halide catalyst differentiates between the in-situ-generated P-species in the A-T process, mainly involving phosphoryl chloride and phosphoric anhydride, thus leading to highly enantiodivergent O-phosphorylation reactions. Furthermore hydrogen bonding interactions between the catalysts and phosphorus molecules were crucial in asymmetric induction.
Light-Enabled Radical 1,4-Aryl Migration Via a Phospho-Smiles Rearrangement
De Abreu, Maxime,Belmont, Philippe,Brachet, Etienne
, p. 3758 - 3767 (2021/02/01)
Rearrangement reactions in organic chemistry are attractive strategies to build efficiently complex scaffolds, in just one step, from simple starting materials. Among them, aryl migrations are certainly one of the most useful and straightforward rearrangement for building attractive carbon-carbon bonds. Of note, anionic aryl migration reactions have been largely described compared to their radical counterparts. Recently, visible-light catalysis has proven its efficiency to generate such radical rearrangements due to the concomitant loss of a particle (often CO2 or SO2), which is the driving-force of the reaction. Here, we disclose a Smiles-type rearrangement, triggered by a phosphorus-containing unit (arylphosphoramidate), therefore called "phospho-Smiles"rearrangement, allowing a Csp2-Csp2 bond formation thanks to a 1,4-aryl migration reaction. In addition, combining this approach with a radical hydroamination/amination reaction produces an amination/phospho-Smiles cascade particularly attractive, for instance, to investigate the synthesis of the phthalazine core, a scarcely described scaffold of interest for medicinal chemistry projects.
