A controlled tandem transformation of conjugated enynones with arenes under superelectrophilic activation leading to aryl-substituted dienones and indenes

Abstract

Under superelectrophilic activation in triflic acid (TfOH) and in the presence of arenes, 1,5-diarylpent-2-en-4-yn-1-ones lead to aryl-substituted indenes with yields up to 97%.

Stereoselective Construction of (E,Z)‐1,3‐Dienes and Its Application in Natural Product Synthesis

“…Initially used by Nakagawa in 1977, [228] the 1,6‐addition of nucleophiles to 4‐yn‐2‐en‐one derivatives is an efficient method for constructing conjugated Z,E ‐dienes; however, they exhibit variable Z selectivities [229–233] . Furthermore, Ooi described in 2018 a spectacular organocatalysed 1,6‐Michael addition of azlactones ( 235 ) to enynyl N ‐acyl pyrazoles ( 236 ) [234] .…”

“…however, they exhibit variable Z selectivities. [229][230][231][232][233] Furthermore, Ooi described in 2018 a spectacular organocatalysed 1,6-Michael addition of azlactones (235) to enynyl N-acyl pyrazoles (236). [234] The use of a P-spiro chiral triaminoiminophosphorane catalyst not only allows the perfect control of the addition regioselectivity (1,6 vs 1,4), but also the Z,Econfiguration of the diene and the enantioselectivity of the quaternary centre in the resulting compounds (237, Scheme 92).…”

Superelectrophiles: Recent Advances

“…The chemistry of enynones has also been studied in superacid promoted conversions [ 45 ]. Aryl-substituted systems are shown to cyclize indanone products in up to 73% yield.…”

Stereoselective Synthesis of Multisubstituted Cyclohexanes by Reaction of Conjugated Enynones with Malononitrile in the Presence of LDA

“…Preparation and characterization of starting enynones 1 has been previously described [34,35]. The general procedure for the synthesis of 4-aryl-2,6-bis(aryletynyl)-4-hydroxy-3-(aryloxomethyl) cyclohexane-1,1-dicarbonitriles (2a-h) and 5-aryl-3-arylethynyl-1-cyano-5-oxopentannitriles (3a,d-f,h) from 1,5-diarylpent-2-en-4-yn-1-ones (1a-h).…”