Unusual Regio‐ and Chemoselectivity in Oxidation of Pyrroles and Indoles Enabled by a Thianthrenium Salt Intermediate

Angewandte Chemie, Journal Year: 2024, Volume and Issue: unknown

Published: June 3, 2024

Abstract A dearomative oxidation of pyrroles to Δ 3 ‐pyrrol‐2‐ones is described, which employs a sulfoxide as oxidant, in conjunction with carboxylic acid anhydride and Brønsted additive. 3‐substituted undergo regioselective give the product isomer oxygen has been introduced at more hindered position. Regioselectivity rationalized by proposed mechanism that proceeds initial thianthrenium introduction less‐hindered pyrrole α‐position, followed distal attack an nucleophile subsequent elimination thianthrene. The same reaction conditions are also able effect chemoselective indoles indolin‐3‐ones additionally 2‐hydroxyindolin‐3‐ones. Here again, regio‐ chemoselectivities through intermediacy salt.

Language: Английский

Pyrrolylsulfonium salts: stable, accessible and versatile pseudohalides for Stille couplings

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 1, 2024

Pyrroles functionalised with a thianthrenium or diphenylsulfonium group undergo Stille couplings aryl alkynyl stannanes in good yields, avoiding the issues of instability that can hamper use analogous pyrrolyl halides.

Language: Английский