One alkyl triphenyl substituted group based phosphonium salt preparation method and application

Abstract

The invention discloses a one alkyl triphenyl substituted group based phosphonium salt preparation method and application. The preparation method includes that a one alkyl triphenyl phosphonium salt halide I is obtained through reaction of several alkyl halides and triphenylphosphine in a DMF (dimethyl formamide) solvent through nucleophilic substitution, and an aqueous solution of a compound I and a sodium tetrafluoroborate aqueous solution are subjected to ion exchange to prepare the phosphonium salt through high yield of recrystallization. The phosphonium salt preparation method and application has the advantages of low cost and easy obtaining of raw materials and low cost, one alkyl triphenyl substituted group containing phosphonium salt II serving as a phase transfer catalyst has the advantages of high catalytic activity, less required dose, long activity time, high thermal stability and low toxicity, high reaction recovery and the like in catalytic fluorine chlorine exchange reaction, and wide commercial application prospect is achieved.

Description

technical field [0001] The invention belongs to the technical field of quaternary phosphonium salt phase transfer catalysts. Specifically relates to a preparation method and application of a quaternary phosphonium salt containing a monoalkyltriphenyl substituent. Background technique [0002] C-F bonds are widely used in pharmaceuticals, pesticides, new materials and biological fields. Due to the high electronegativity and small atomic radius of fluorine atoms, it is very difficult to introduce fluorine atoms at specific positions in organic matter. Halogen exchange fluorination is currently the most widely used and researched fluorination method in industry. Phase transfer catalyst is the key to the development of halogen exchange fluorination. Crown ether, polyether, quaternary ammonium salt and quaternary phosphonium salt catalyst are halogen Four main catalysts for exchange fluorination. [0003] Crown ether and chain ether catalysts are PTCs that were used earlier. I...

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Problems solved by technology

[0003] Crown ether and chain ether catalysts are PTCs that were used earlier. In the halogen exchange reaction, they form complexes with alkali metal cations to form "naked" F - Ions and crown ethers are characterized by high catalytic activity, good thermal and chemical stability, but are expensive and highly toxic, and are mainly used in conjunction with other catalysts in halogen exchange reactions; polyethers (such as PEG) are cheap and toxic Small, good chemical stability, often used as a substitute catalyst for crown ethers and quaternary ammonium salts, but thermal stability is poor, Ji Woong Lee, Hailong Yan et al. (Ji Woong Lee, Hailong Yan, Hyeong Bin Jang, Hong Ki Kim.Bis -TerminalHydroxy Polyethers as All-Purpose, Multifunctional Organic Promoters: A Mechanistic Investigation and Applications.Angew.Chew.Int.Ed.2009, 48:7683-7686.) Crown ethers and crown ethers were applied to the fluorine-chlorination exchange reaction, and the product was obtained Rate all only reaches 40%; Quaternary ammonium salt catalytic activity is high, but thermal stability is poor, when temperature exceeds 100 ℃, begin to decompose, easily produce by product Dong Wook Kim, Hwan-Jeong Jeong etc. (Dong Wook Kim, Hwan-JeongJeong, Seok Tae Lim, Myung-Hee Sohn. Facile nucleophilic fluorination of primary alkyl halides using tetrabutylammonium fluoride in a tert-alcohol medium. Tetrahedron Letters 2010, 51: 432-434.) Apply quaternary ammonium salts to the fluorine-chlorine exchange reaction to obtain Product yield is also only 56%

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