40927-82-0Relevant academic research and scientific papers
Deprotonation of furans using lithium magnesates
Mongin, Florence,Bucher, Aurélien,Bazureau, Jean Pierre,Bayh, Omar,Awad, Ha?an,Trécourt, Fran?ois
, p. 7989 - 7992 (2005)
Furan was deprotonated on treatment with 1/3 equiv of Bu3MgLi in THF at rt. The lithium arylmagnesate formed was either trapped with electrophiles or involved in a palladium-catalyzed cross-coupling reaction with 2-bromopyridine. The highly coordinated magnesate Bu4MgLi2 (1/3 equiv) proved to be a better deprotonating agent than Bu3MgLi; the monitoring of the reaction using NMR spectroscopy showed that the deprotonation of furan at rt required 2 h whereas the subsequent electrophilic trapping was instantaneous. The method was extended to benzofuran, allowing its functionalization at C2 in high yields. The deprotonation of 2-methylfuran and lithium furfurylalkoxide at C5 turned out to be difficult, requiring either long reaction times or higher temperatures.
A Wittig reaction with 2-furyl substituents at the phosphorus atom: Improved (Z) selectivity and isolation of a stable oxaphosphetane intermediate
Appel, Marco,Blaurock, Steffen,Berger, Stefan
, p. 1143 - 1148 (2007/10/03)
Wittig reactions with ylides bearing one, two or three 2-furyl groups directly bound to the phosphorus atom have been studied. Greatly improved (Z)-alkene selectivities of up to 98:2 could be observed if 2-furyl groups were present. Monitoring of the reactions by NMR spectroscopy revealed only oxaphosphetane intermediates, which became more stable with increasing number of 2-furyl substituents bound to the phosphorus atom. Oxaphosphetane 10d, with three furyl groups, was successfully isolated, and the results of a crystal structure analysis are presented. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
Water-soluble derivatives of furylphosphanes
Eymery, Frederic,Burattin, Paolo,Mathey, Francois,Savignac, Philippe
, p. 2425 - 2431 (2007/10/03)
(2-Furyl)diphenylphosphane (1), bis(2-furyl)phenylphosphane (8) and tris(2-furyl)phosphane (9) have been converted into their water soluble 5- carboxylates 4, 11 and 12, 5-phosphonates 14 and 16 and 5-sulfinates 17-19. In most cases, the selected route involved a 5-bromo to 5-lithio exchange reaction, followed by reaction with CO2, CIP(O)(OEt)2 or SO2. The furan group sharply enhances the water-solubility of these products when compared with the corresponding benzene derivatives. Catalytic tests in hydrogenation, hydroformylation and Heck cross-coupling reactions showed that the sulfinate group tends to inhibit the catalysis and, in addition, a sharp drop in activity was observed with the trifunctional products 12 and 10. Overall, the phosphonates 14 and 16 appear to be the most promising ligands for biphasic catalysis.
