4982-08-5Relevant articles and documents
Copper-Mediated Dichotomic Borylation of Alkyne Carbonates: Stereoselective Access to (E)-1,2-Diborylated 1,3-Dienes versus Traceless Monoborylation Affording α-Hydroxyallenes
Guo, Kun,Kleij, Arjan W.
supporting information, p. 4901 - 4906 (2021/01/21)
A mild copper-mediated protocol has been developed for borylation of alkynyl cyclic carbonates. Depending on the nature of the borylating reaction partner, either stereoselective diborylation of the propargylic surrogate takes place, providing convenient access to (E)-1,2-borylated 1,3-dienes, or traceless monoborylation occurs, which leads to α-hydroxyallenes as the principal product. The dichotomy in this borylation protocol has been scrutinized by several control experiments, illustrating that a relatively small change in the diboron(4) reagent allows for competitive alcohol-assisted protodemetalation to forge an α-hydroxyallene product under ambient conditions.
The Power of Triplet and Singlet Oxygen in Synthesis: 2-Oxindoles, 3-Hydroxy-2-oxindoles, and Isatins from Furans
Triantafyllakis, Myron,Sfakianaki, Kalliopi,Kalaitzakis, Dimitris,Vassilikogiannakis, Georgios
supporting information, p. 3631 - 3634 (2018/06/26)
A straightforward synthesis of substituted 2-oxindoles, 3-hydroxy-2-oxindoles, and isatins has been developed. Easily accessible furans were transformed into tetrahydropyranopyrrolones by a singlet oxygen initiated cascade reaction sequence. An acid-catal
Total synthesis of (+)-phenguignardic acid, a phytotoxic metabolite of Guignardia bidwellii
Stoye, Alexander,Kowalczyk, Danuta,Opatz, Till
, p. 5952 - 5960 (2013/09/23)
(+)-Phenguignardic acid, a phytotoxic metabolite of the grape black rot fungus Guignardia bidwellii was synthesized, as well as its enantiomer, in eight steps from (R)-phenyllactic acid and 3-phenylprop-2-yn-1-ol. The formation of the carboxylate at a late stage, to avoid enolization of the precursor used in the central acetalization step, proved to be crucial. The synthesis of the natural product allowed the unabiguous assignment of its hitherto unknown absolute configuration. (+)-Phenguignardic acid, a potent phytotoxic metabolite of Guignardia bidwellii, was synthesized, as well as its enantiomer, in eight steps from (R)-phenyllactic acid and 3-phenylprop-2-yn-1-ol. The absolute configuration of the natural product was determined to be S. Copyright
