BENZYLDIPHENYLPHOSPHINE

Description

Benzyldiphenylphosphine is a tertiary organophosphine in which the phosphorus atom is bonded to two phenyl groups and one benzyl group. Formula C19H17P, CAS number 7650-91-1, synonyms diphenylbenzylphosphine, diphenyl(phenylmethyl)phosphine.

Basic Attributes

• Chemical formula: C19H17P
• Molecular weight: 276.31
• Exact weight: 276.106781
• EC number: 1312995-182-4
• DSSTox ID: DTXSID90345351
• HS code: 2931900090
• PSA Features: 0
• XLogP3: 4.5

Physico-chemical characteristics

• Appearance: White to dark white powder
• Melting point: 77-83 °C (lit.)
• Boiling point: 399.6 °C at 760 mm Hg. Art.
• Flash point: 206.2±28.3°C
• Solubility in water: slightly soluble

Scope of application

Tertiary phosphines of this type are used as ligands in transition metal catalysis: the phosphorus atom coordinates palladium, nickel and rhodium, forming catalytic complexes for cross-coupling, hydroformylation and hydrogenation reactions. The presence of a benzyl group containing acidic protons in the alpha position to the phosphorus atom also makes the compound a convenient precursor for the preparation of benzylphosphonium salts and Wittig ylides after quaternization and deprotonation - such derivatives are used in olefination reactions in the construction of new carbon-carbon double bonds.

Safety Information

• Transport codes: NONH for all modes of transport
• WGK Germany: 3
• Hazard class code: 36/37/38-22
• Safety instructions: 37/39-26
• Tags: Xn

Storage conditions

Tertiary phosphines are sensitive to oxidation by atmospheric oxygen to form the corresponding phosphine oxides, so the substance is stored in a tightly closed container in an inert atmosphere or under conditions that minimize contact with air in a cool, dry place. When working, use protective gloves and goggles, avoiding inhalation of dust due to its irritating effect on the skin, eyes and respiratory tract.

Role in metal complex catalysis

Mixed phosphines, combining aromatic and benzyl substituents, make it possible to finely tune the electronic and steric properties of the metal center of the catalytic complex: phenyl groups provide moderate donation and steric protection of the metal, and the benzyl group introduces additional flexibility of the coordination sphere and opens the way to subsequent functionalization of the ligand itself without destruction of the metal complex. Such ligands are used in the development of catalysts for asymmetric hydrogenation and coupling reactions in the synthesis of pharmaceutical substances.

When storing and transporting the reagent, avoid contact with strong oxidizing agents and acids that can initiate the oxidation of tertiary phosphine to the corresponding phosphine oxide. The selection of the optimal ligand remains the subject of targeted empirical optimization for a specific catalytic system.