Premium
Chemoselective Ketone Synthesis by the Strontium‐mediated Alkylation or Arylation of N , N ‐Dimethylamides or Urea
Author(s) -
Miyoshi Norikazu,
Kimura Shodai,
Kubo Shigeki,
Ohmura Satoshi D.,
Ueno Masaharu
Publication year - 2020
Publication title -
asian journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.846
H-Index - 44
eISSN - 2193-5815
pISSN - 2193-5807
DOI - 10.1002/ajoc.202000389
Subject(s) - chemistry , ketone , alkylation , reagent , nucleophile , benzophenone , electrophile , organic chemistry , amide , solvent , alkyl , medicinal chemistry , catalysis
Ketone synthesis via the addition of organometallic reagents to amides has long been investigated. In many cases, it is necessary to control the solvent, reaction temperature, and adhere to strict nucleophile stoichiometry for each combination of amide and organometallic reagent. Strontium, with an electronegativity comparable to lithium but a larger ionic radius, may display high reactivity with the characteristics of monoalkylation. Here, we show that the monoalkylation of various N , N ‐dimethylamide derivatives with alkyl iodides to afford the ketones proceeds smoothly under generally mild temperature conditions. By this method, not only aromatic amides but also α‐proton‐bearing aliphatic amides were suitable substrates for ketone synthesis. In addition, we found that tetramethylurea, typically a poor electrophile, also reacted to afford benzophenone in good yield with excellent selectivity.