ПОЛИ (ЭТИЛЕНГЛИКОЛЬ) ТРИФЕНИЛФОСФИН

Description

Poly(ethylene glycol) triphenylphosphine is a triarylphosphine reagent attached to a polyethylene glycol chain. Such a carrier is soluble in polar media, so the reaction occurs in a homogeneous phase, as with ordinary triphenylphosphine, and isolation is carried out by precipitation of the polymer with diethyl ether or cold isopropanol. This combines the convenience of liquid-phase synthesis with the ease of separation characteristic of reagents on an insoluble polystyrene support. Sigma-Aldrich catalog product 532649.

Basic Attributes

• CAS No.: 238403-28-6
• Chemical formula: C20H21O2P
• Molecular weight: 324.353301
• Exact weight: 324.128

Characteristics

• PSA: 40.5
• Melting point: 44–46 °C (lit.)

Purpose

• ligand for palladium catalysis in cross-coupling reactions: Suzuki - Miyaura, Buchwald - Hartwig, Stille, Sonogashira, Negishi, Heck, Hiyama
• hydrogenation catalyst in a two-phase water-substrate system
• phosphine reagent of classical transformations: Mitsunobu, Wittig, reduction of azides according to Staudinger
• liquid-phase organic synthesis and combinatorial chemistry, where the reagent and by-product phosphine oxide are removed by precipitation of the carrier

Advantages of a polymer carrier

The main difficulty in working with triphenylphosphine is the separation of the resulting triphenylphosphine oxide from the product: it is difficult to remove during chromatography and crystallization. When phosphine is attached to polyethylene glycol, the oxide remains bound to the polymer, and both leave the reaction mixture when the support is deposited, simplifying purification and allowing the reagent to be recycled. Unlike cross-linked polystyrene resins, the soluble PEG carrier does not create diffusion restrictions, so the reaction rate remains close to homogeneous.

Safety Information

• WGK Germany: 3

Storage and handling

Phosphines are oxidized by atmospheric oxygen, so the reagent is kept in a tightly closed container, if possible under an inert gas, and in a cool place: melting point 44–46 °C; when heated, the product softens. Do not allow discharge into water bodies - aquatic hazard class WGK 3.