An acetylene zipper—Sonogashira reaction sequence for the efficient synthesis of conjugated arylalkadiynols

Electrophilic Cyclization of Aryldiacetylenes in the Synthesis of Functionalized Enediynes Fused to a Heterocyclic Core

“…The most efficient synthetic route to this type of compound is the Sonogashira coupling of ortho -functionalized iodoarenes 3a – g with terminal diacetylenes (Table ). Terminal diacetylenes with alkyl ( 2a ) and hydroxyalkyl substituents ( 2b – d ) were easily obtained by treatment of corresponding internal diacetylene compounds 1a – d with lithium 2-aminoethylamide (LAETA) (diacetylene zipper reaction) (Table , Method A), which were then used without purification in Cu/Pd-catalyzed cross-coupling. This route was employed in the synthesis of the corresponding thioanisoles 4a – d (Table , entries 1–4), anilines 5a and 6a – c (Table , entries 9, 11–13), and O -alkylated phenols 7a , c (Table , entries 14, 16).…”

Practical, high-yield synthesis of thiol-terminated diacetylenes for formation of conductive monolayers

“…2, 5–7 One approach to forming 2-dimensional conductive materials of polyacetylene is to pre-form self-assembled monolayers (SAM) of monomeric precursors to the polymer and then polymerize these into the film using UV light (Scheme 1). 1, 8–11 The key to the practical applications of 2-dimensional polyacetylene films by the SAM approach is the efficient synthesis and purification of the thiol terminated hydrocarbon containing conjugated diacetylenes. Changing the functional group designed to bind to the surface affords compounds that form SAMs on other substrates, for example phosphates bound to group III nitrides, 12 carboxylates bound to indium tin oxide, 13 or insulators such as sapphire or highly ordered pyrolytic graphite.…”

“…Similar approaches to the synthesis of diacetylene alcohol were reported later, including a 14-(9H-9-carbazolyl)-tetradeca-10,12-diyn-1-yl disulfide, and the henicosa-10,12-diyn-1-yl disulfide. 11, 18 Wolf and coworkers use a much larger monomer based on a propionic ester, [S(CH 2 ) 2 COO(CH 2 ) 9 CC-CC(CH 2 ) 13 CH 3 ] 2 deposited as the disulfide, and presumably the enhanced intermolecular interactions of the liquid crystal forming monomers aids in the formation of ordered films. 19…”

“…Next, we attempted to form the unsymmetrical diacetylene thiols via a Cadiot Chodkiewicz type reaction starting with alkynes 11, 17 using Cu(I) as catalyst forming iodoalkyne in situ , 23 but no product was observed.…”