Pd-Catalyzed Cyanoselenylation of Internal Alkynes: Access to Tetrasubstituted Selenoenol Ethers

Abstract

The intra-and intermolecular synthesis of selenium-substituted acyclic and heterocyclic acrylonitrile derivatives is presented. The 1,2-difunctionalization of several internal alkynes substituted not only by aliphatic and aromatic residues but also by heteroelements is realized by the Pd-catalyzed activation of aromatic and aliphatic selenocyanates. A high functional group tolerance allows straightforward access to a broad scope of tetrasubstituted olefins. X-ray studies of some products reveal noncovalent chalcogen−chalcogen interactions between oxygen and selenium.

Methyl groups as widespread Lewis bases in noncovalent interactions

“…6b ). We also show an interesting example of chalcogen bonding (ZUNXIS 51 , Fig. 6c ) between a methyl group and a selenium atom.…”

Redox‐Neutral Selenium‐Catalysed Isomerisation of para‐Hydroxamic Acids into para‐Aminophenols

“…[8][9][10] Within organic synthesis, organoselenium reagents have also emerged as unique catalysts for oxidation, [11] reduction, [12] C À C/C À X bond formation and rearrangements. [13][14][15] The heavier selenium shows distinct properties when compared to the other chalcogens. [16] Herein we present a new seleniumcatalysed, redox-neutral para-selective hydroxylation starting from hydroxamic acids via consecutive [2,3]-rearrangements to form para-aminophenols (Scheme 1 f).…”

Supramolecular aggregation patterns featuring Se⋯N secondary-bonding interactions in mono-nuclear selenium compounds: A comparison with their congeners

“…17b brought forth by the proximity of the bulky substituents. A different topology for the supramolecular tapes is observed in the crystals of 112 [101], 113 [142] and 114 [143], being based on edge-shared rectangles. The three molecules are organoselenium cyanates.…”