Photocatalyst‐Free Photochemical Trifluoromethylation/Cyclization of Unactivated Alkenes: Synthesis of Trifluoromethyl‐Substituted Quinazolinones

A novel photochemical trifluoromethylation/cyclization of unactivated alkenes to synthesize trifluoromethyl‐substituted quinazolinones with trifluoromethylsulfonyl‐pyridinium salt (TFSP) is achieved under catalyst‐free conditions. Mechanistic studies reveal that an electron‐donating‐accepting complex is formed between the quinazolinone and TFSP, making this the first example of TFSP‐based trifluoromethylation conducted in the absence of expensive iridium photocatalysts.