Visible-light-mediated dehydrogenative cross-coupling between terminal alkynes and aldehydes by employing a supramolecular polymeric ensemble of PBI derivative

Abstract

A supramolecular polymer of PBI derivative and ZnO NPs exhibits remarkable efficiency in direct dehydrogenative cross-coupling reaction for the synthesis of ynones under photocatalytic conditions.

Cross‐Dehydrogenative Alkynylation: A Powerful Tool for the Synthesis of Internal Alkynes

“…The role of In(OTf) 3 was unclear in the reaction but it might assist in the activation of terminal alkynes and aldehydes. By employing ZnO nanoparticles immobilized on a supramolecular polymer of a perylene bisimide derivative as a heterogeneous photocatalyst, the aromatic aldehydes could also cross‐dehydrogenatively couple with terminal alkynes, forming the corresponding ynones under photocatalytic conditions . In the reaction, the excessive aldehydes (2.5 equiv) acted as hydrogen acceptors.…”

‘Lighted’ Assemblies of a PBI Derivative: Activation of Aerial Oxygen via Combined Charge and Energy Transfer Processes for Photocatalytic Oxidative Hydroxylation of Boronic Acids

“…In the presence of 40% water fractions, a decrease in the intensity of emission band is observed (Figure S5). The concentration depended 1 H‐NMR studies and absorption studies of PBI‐TPY indicate the formation of J‐type assemblies [29] . The time resolved fluorescence studies of PBI‐TPY in acetonitrile show a biexponential decay where major fraction (84%) shows a life time of 1.83 ns.…”

“…The bay functionalized perylene bisimide derivative ( PBI‐TPY ) (Scheme 2(a)) was synthesized by a method already reported in the literature [29] …”

“…We further expect that weakly basic terpyridyl groups may enhance the affinity of molecules of PBI derivative towards boronic acid and the enhanced catalyst‐reactant proximity may influence the reaction positively. Recently, we reported the synthesis of PBI‐TPY derivative having terpyridyl groups at the periphery which exhibited strong absorption in the visible region [29] …”

“…Recently, we reported the synthesis of PBI-TPY derivative having terpyridyl groups at the periphery which exhibited strong absorption in the visible region. [29] To assess the validity of our hypothesis, we planned to investigate the catalytic efficiency of PBI-TPY in the oxidative hydroxylation of boronic acid. Before starting the catalytic investigations, we determined the HOMO-LUMO gap and the energy difference (ΔE ST ) in the single-triplet excited state of PBI-TPY in gaseous state, using density functional theory.…”