A Highly Selective Synthesis of 1,1′-Bi-2-naphthol by Oxidative Coupling of Naphthol on Mesoporous Fe,Cu/MCM-41 Aluminosilicates
✍ Scribed by Elvira Armengol; Avelino Corma; Hermenegildo García; Jaime Primo
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 316 KB
- Volume
- 1999
- Category
- Article
- ISSN
- 1434-193X
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✦ Synopsis
The oxidative coupling of 2-naphtol to 2,2Ј-dihydroxy-1,1Ј-it cannot diffuse outside the zeolite cavities through the smaller pore apertures (0.74 nm). This prediction has been binaphthyl (binaphthol) by air or oxygen has been carried out in the presence of Cu 2+ -and Fe 3+ -doped MCM-41 confirmed by dissolving a Y zeolite after the reaction, whereby unextractable binaphthol entrapped within the aluminosilicate as catalyst. Fe-exchanged MCM-41 was found to be a very efficient catalyst; excellent mass balances cavities was recovered. Variable amounts of two secondary by-products have also been detected, and their structure (Ͼ 95%) with almost total conversion and selectivity to binaphthol were achieved. The same reaction has also been assigned to (2,8Ј);(8,2Ј)-dioxo-1,1Ј-binaphthyl and bisnaphthofuran based on analytical and spectroscopic data. carried out on Cu 2+ -and Fe 3+ -Y zeolites. Taking into account the relative dimensions of binaphthol and the catalyst pores, Their percentage is particularly high when aluminasupported CuSO 4 is used as the catalyst. molecular modeling predicts that binaphthol can be accommodated inside the zeolite Y supercages (1.3 nm), but [a] Instituto de Tecnologı ´a Quı ´mica CSIC-UPV, Universidad Polite ´cnica de Valencia, case the transition-metal ions) are located in the interior of E-46071 Valencia, Spain the pores. Hence, zeolites are generally efficient catalysts