Osmium(0)-Catalyzed C–C Coupling of Ethylene and α-Olefins with Diols, Ketols, or Hydroxy Esters via Transfer Hydrogenation
| Autor: | Boyoung Y. Park, Hiroki Sato, Michael J. Krische, Tom Luong |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Ethylene
010405 organic chemistry Organic Chemistry Diol chemistry.chemical_element Regioselectivity 010402 general chemistry Transfer hydrogenation 01 natural sciences Medicinal chemistry 0104 chemical sciences Catalysis chemistry.chemical_compound chemistry XPhos Organic chemistry Osmium Oxidative coupling of methane |
| Zdroj: | The Journal of Organic Chemistry. 81:8585-8594 |
| ISSN: | 1520-6904 0022-3263 |
| DOI: | 10.1021/acs.joc.6b01923 |
| Popis: | Osmium(0) complexes derived from Os3(CO)12 and XPhos (2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl) catalyze the C–C coupling of α-hydroxy esters 1a–1i, α-ketols 1j–1o, or 1,2-diols dihydro-1j–1o with ethylene 2a to form ethylated tertiary alcohols 3a–3o. As illustrated in couplings of 1-octene 2b with vicinally dioxygenated reactants 1a, 1b, 1i, 1j, 1k, 1m, higher α-olefins are converted to adducts 4a, 4b, 4i, 4j, 4k, 4m with complete levels of branched regioselectivity. Oxidation level independent C–C coupling is demonstrated by the reaction of 1-octene 2b with diol dihydro-1k, α-ketol 1k, and dione dehydro-1k. Functionalized olefins 2c–2f react with ethyl mandelate 1a to furnish adducts 5a–8a as single regioisomers. The collective data, including deuterium labeling studies, are consistent with a catalytic mechanism involving olefin–dione oxidative coupling to form an oxa-osmacyclopentane, which upon reductive cleavage via hydrogen transfer from the secondary alcohol reactant releases the produ... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|