The B12âTiO2 hybrid catalyst was effectively used for the radical reactions, such as 1,2-migrations of phenyl groups and acyl groups under irradiation by UV light, and the selectivity of the reaction was controlled by the solvent system.
First example of samarium diiodide-promoted sequential cyclization and ring-expansion reactions of α-bromomethyl cyclic β-keto esters to homologated γ-keto esters
SmI2 reductions of some aromatic as well as aliphatic alpha-bromomethyl cyclic beta-keto esters produced one-carbon homologated gamma-keto esters in modest to good yields. (C) 1998 published by Elsevier Science Ltd. All rights reserved.
Electroorganic chemistry. 124. Electroreductive intramolecular coupling of .alpha.-(.omega.-bromoalkyl) .beta.-keto esters
The reaction of cyclic beta-keto esters with CF3CO2ZnCH2I provided the corresponding ring-expanded products in moderate to good yields. Although alpha-substituted acyclic beta-keto esters reacted with much less efficient, chain-extension reaction of simple beta-keto esters also proceeded effectively to generate gamma-keto esters in high yields.
Reductive transformation of α,β-epoxy ketones and other compounds promoted through photoinduced electron transfer processes with 1,3-dimethyl-2-phenylbenzimidazoline (DMPBI)
Photoreactions of epoxy ketones, aromatic ketones, haloketones, and aromatic halides with 1,3-dimethyl-2-phenylbenzimidazoline (DMPBI) were studied Photoinduced single-electron transfer from DMPBI to such substrates initiates the reactions followed by radical radical rearrangement and reduction to finally give several reduced products in modest to good yields. (C) 1999 Elsevier Science Ltd. All rights reserved.