42337-03-1Relevant articles and documents
Photoredox Allylation Reactions Mediated by Bismuth in Aqueous Conditions
Potenti, Simone,Gualandi, Andrea,Puggioli, Alessio,Fermi, Andrea,Bergamini, Giacomo,Cozzi, Pier Giorgio
, p. 1624 - 1627 (2021)
Organometallic allylic reagents are widely used in the construction of C?C bonds by Barbier-type reactions. In this communication, we have described a photoredox Barbier allylation of aldehydes mediated by bismuth, in absence of other metals as co-reductants. Mild reaction conditions, tolerance of oxygen, and use of aqueous solvent make this photoredox methodology attractive for green and sustainable synthesis of homoallylic alcohols.
Catalytic Photoredox Allylation of Aldehydes Promoted by a Cobalt Complex
Gualandi, Andrea,Rodeghiero, Giacomo,Perciaccante, Rossana,Jansen, Thomas Paul,Moreno-Cabrerizo, Cristina,Foucher, Charles,Marchini, Marianna,Ceroni, Paola,Cozzi, Pier Giorgio
supporting information, p. 1105 - 1111 (2021/01/04)
The preparation of homoallylic alcohols by addition of organometallic allyl compounds to carbonyls is an important strategy in organic chemistry. Allylating organometallic cobalt species can be generated employing stoichiometric quantities of Zn acting as reductant. To avoid the employment of stoichiometric amount of Zn, we have developed an allylation reaction of aromatic and aliphatic aldehydes promoted by photoredox catalysis in the presence of a cobalt complex, and we present herein a full account of our research. In the presence of the abundant CoBr2 (10 mol %), 4,4′-di-tert-butyl-2,2′-dipyridyl (dtbbpy, 10 mol %), allyl acetate (3 equiv.), [Ir(dtbbpy)(ppy)2]PF6 (ppy=2-phenylpyridine, 2 mol %), and N,N-diisopropylethylamine (4 equiv.), an allylation of aldehydes is taking place, in moderate to good yields. Substrates scope, limitations, and photophysical investigations of this new process are reported. (Figure presented.).
Cu-catalyzed hydroxycyclopropanol ring-opening cyclization to tetrahydrofurans and tetrahydropyrans: short total syntheses of hyperiones
Liang, Weida,Cai, Xinpei,Dai, Mingji
, p. 1311 - 1316 (2021/02/12)
Tetrahydrofurans (THFs) and tetrahydropyrans (THPs) are important core scaffolds frequently found in many molecules of medicinal importance. Herein, we report a novel copper-catalyzed hydroxycyclopropanol ring-opening cyclization methodology to synthesize di- or tri-substituted THFs and THPs. In this reaction, a strained C-C bond was cleaved and a new Csp3-O bond was formed to produce the aforementioned O-heterocycles. The new THF synthesis features a broad substrate scope, scalability, and good functional-group tolerability. It enabled us to complete the shortest enantioselective syntheses of hyperiones A and B (3 and 4 steps, respectively), which is significantly shorter than the previously reported two total syntheses (≥10 steps).
