α‐Halocarbonyls as a Valuable Functionalized Tertiary Alkyl Source

Abstract

This review introduces the synthetic organic chemical value of α‐bromocarbonyl compounds with tertiary carbons. This α‐bromocarbonyl compound with a tertiary carbon has been used primarily only as a radical initiator in atom transfer radical polymerization (ATRP) reactions. However, with the recent development of photo‐radical reactions (around 2010), research on the use of α‐bromocarbonyl compounds as tertiary alkyl radical precursors became popular (around 2012). As more examples were reported, α‐bromocarbonyl compounds were studied not only as radicals but also for their applications in organometallic and ionic reactions. That is, α‐bromocarbonyl compounds act as nucleophiles as well as electrophiles. The carbonyl group of α‐bromocarbonyl compounds is also attractive because it allows the skeleton to be converted after the reaction, and it is being applied to total synthesis. In our survey until 2022, α‐bromocarbonyl compounds can be used to perform a full range of reactions necessary for organic synthesis, including multi‐component reactions, cross‐coupling, substitution, cyclization, rearrangement, stereospecific reactions, asymmetric reactions. α‐Bromocarbonyl compounds have created a new trend in tertiary alkylation, which until then had limited reaction patterns in organic synthesis. This review focuses on how α‐bromocarbonyl compounds can be used in synthetic organic chemistry.