Lewis Acid-Catalyzed Diastereoselective Hydroarylation of Benzylidene Malonic Esters

Abstract

Herein we report that simple Lewis acids catalyze the hydroarylation of benzylidene malonates with phenols. Ultimately, 3,4-disubstituted dihydrocoumarins are obtained via a hydroarylation-lactonization sequence. Moreover, the dihydrocoumarins are formed with a high degree of diastereoselectivity favoring the trans stereoisomer.

Domino Hydroarylation–Cyclization Reaction: One‐Pot Synthesis of Indane‐Fused 3,4‐Dihydrocoumarins

“…However, despite extensive experimentations, only starting materials could be detected or isolated after examining a wide variety of Lewis/Brønsted acid promoters and reaction conditions (Scheme ). At this juncture, we reasoned the lack of reactivity could be remedied by introducing an additional carboxylate group to enhance the electrophilicity of the cinnamate olefin, and concomitantly provide a bi‐dentate binding site to the Lewis/Brønsted acid promoter 7d,11. Gratifyingly, the revised substrate ( 1a ) underwent smooth coupling and ring formations with 3‐methoxyphenol in the presence of 5 mol% of Sn(OTf) 2 to afford compound 2aa in 74% yield (Table 1, entry 1) 12.…”

Syntheses and Biological Activities of Chroman-2-ones. A Review

“…159 They have also proved mechanistically the most probable sequence of the reaction to be hydroarylation followed by transesterification. Reaction of phenol and its derivatives with 2-(trifluoromethyl)acrylic acid in the presence of excess of triflic acid to give 3,4-dihydro-3-trifluoromethyl-2H-1-benzopyran-2-ones has been described by Surya Prakash et al 160 Activated phenols reacted more rapidly compared to unactivated phenols, which gave mainly uncyclized vinyl aryl esters.…”

New receptors for the detection of organic contaminants in sea water

“…The 3D modeled structures of the ligands and substrates were built using the Cambridge Soft ChemBio3D Ultra 11.0 program [7]. To these initial structures of the ligands and substrates all hydrogen atoms were added and the geometry optimization was carried out using MMFF94 Force Field; Algorithm steepest descent [8].…”