Palladium-Catalyzed Intermolecular Alkene Carboacylation via Ester C–O Bond Activation
作者:Haley K. Banovetz、Kevin L. Vickerman、Colton M. David、Melisa Alkan、Levi M. Stanley
DOI:10.1021/acs.orglett.1c00940
日期:2021.5.7
We report palladium-catalyzed intermolecular carboacylation of alkenes with ester electrophiles and tetraarylborate nucleophiles. Bicyclic alkenes react with a variety of pentafluorophenyl benzoate and alkanoate esters and sodium tetraarylborates to form ketone products in ≤99% yields. These reactions occur in the absence of a directing group and demonstrate esters are competent acyl electrophiles
A Polar Effects Controlled Enantioselective 1,2-Chlorine Atom Migration via a Chlorine-Bridged Radical Intermediate
作者:Eng Wui Tan、Bun Chan、Allan G. Blackman
DOI:10.1021/ja011129r
日期:2002.3.1
An enantioselective 1,2-chlorine atom migration was observed in the tributyltin hydride reduction of various dihalogenated dihydrocinnamic acid derivatives. It is proposed that the reduction involves the formation of a chlorine-bridged radical intermediate, followed by hydrogen atom transfer to either the beta- or the alpha-carbon. The product distribution is affected by electron-withdrawing groups
Primary alcohols and chiral N-protected 2-amino alcohols can be obtained in high yields from the reaction of pentafluorophenyl esters of the corresponding carboxylic acids with sodium borohydride in THF under mild conditions. This reductive method is rapid and compatible with various functional groups as well as with the most common N-protective groups Z, Boc and Fmoc.
Highly enantioselective catalytic asymmetric epoxidation of α,β-unsaturatedcarboxylic acid imidazolides and simple amides was developed. In the presence of 5–10 mol% of lanthanide–BINOL complexes, the reaction proceeded smoothly with high substrate generality. In particular, in the cases of α,β-unsaturated amides, there was nearly perfect enantioselectivity (>99% ee). The corresponding epoxides were
Synthesis of mixed acyclic imides using pentafluorophenyl esters
作者:Merritt B. Andrus、Wenki Li、Robert F. Keyes
DOI:10.1016/s0040-4039(98)01112-5
日期:1998.7
Mixed acyclicimides are assembled using amide anions and pentafluorophenyl esters reacted in THF at low temperature. Sodium hexamethyldisilazide deprotonates lactam 4 followed by addition of pentafluorophenyl (PFP) esters to give imides in high yield (85–90%). Acyclic TMS-protected primary amides were also reacted under basic conditions with PFP esters to give mixed imides.