Entropy‐Induced Selectivity Switch in Gold Catalysis: Fast Access to Indolo[1, 2‐a]quinolines. Issue 55 (1st August 2022)

• Record Type: Journal Article
• Authors: Heckershoff, Robin; May, Garrett; Däumer, Janika; Eberle, Lukas; Krämer, Petra; Rominger, Frank; Rudolph, Matthias; Mulks, Florian F.; Hashmi, A. Stephen K.
• Is Part Of: Chemistry. Volume 28:Issue 55(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-08-01
• Subjects: gold catalysis -- material science -- nitrogen heterocycles -- photophysics -- selectivity switch; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202201816
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: New N‐heterocyclic compounds for organic functional materials and their efficient syntheses are highly demanded. A surprising entropy‐induced selectivity switch in the gold‐catalyzed intramolecular hydroarylation of 2‐ethynyl N ‐aryl indoles was found and its exploitation led to straightforward syntheses of indolo[1, 2‐ a ]quinolines. Experimental and computational mechanistic investigations gave insight into this uncommon selectivity phenomenon and into the special reactivity of the indolo[1, 2‐ a ]quinolines. The high functional group tolerance of this methodology enabled access to a diverse scope with high yields. In addition, bidirectional approaches, post‐functionalization reactions, and π‐extension of the core structure were feasible. An in‐depth study of the photophysical properties explored the structure‐effect relationship for different derivatives and revealed a high potential of these compounds for future applications as functional materials. Abstract : An entropy‐induced selectivity switch in the gold‐catalyzed hydroarylation of 2‐ethynyl N ‐aryl indoles was discovered, and the investigation by experimental and computational mechanistic studies led to a full explanation of the observed temperature‐dependent selectivity. The in this context introduced methodology allows versatile access to indolo[1, 2‐ a ]quinolines, which are highly fluorescent dyes with appealing photophysical properties making them promising candidates for OLED applications.