(). 2-iodoxybenzoic acid in DMSO performs similarly. As a protecting group Benzyl groups are occasionally employed as protecting groups in organic synthesis. Their installation and especially their removal require relatively harsh conditions, so benzyl is not typically preferred for protection. Alcohol protection Benzyl is commonly used in organic synthesis as a robust protecting group for alcohols and carboxylic acids. Treatment of alcohol with a strong base such as powdered potassium hydroxide or sodium hydride and benzyl halide (BnCl or BnBr) Monobenzylation of diols can be achieved using Ag2O in dimethylformamide (DMF) at ambient to elevated temperatures Primary alcohols can be selectively benzylated in presence of phenol functional groups using Cu(acac)2 Deprotection methods Benzyl ethers can be removed under reductive conditions, oxidative conditions, and the use of Lewis Acids. Removed using hydrogenolysis Single electron process with Na/NH3 or Li/NH3 Benzyl protecting groups can be removed using a wide range of oxidizing agents including: CrO3/acetic acid at ambient temperature Ozone N-Bromosuccinimide (NBS) N-Iodosuccinimide (NIS) Trimethylsilyl iodide (Me3SiI) in dichloromethane at ambient temperature (selectivity can be achieved under specific conditions) The p-methoxybenzyl protecting group p-Methoxybenzyl (PMB) is used as a protecting group for alcohols in organic synthesis (4-Methoxybenzylthiol is used to protect thiols). Strong base such as powdered potassium hydroxide or sodium hydride and p-methoxybenzyl halide (chloride or bromide) 4-methoxybenzyl-2,2,2-trichloroacetimidate can be used to install the PMB group in presence of: Scandium (III) triflate (Sc(OTf)3) in toluene at 0 °C Trifluoromethanesulfonic acid (TfOH) in dichloromethane at 0 °C Deprotection methods 2,3-Dichloro-5,6-dicyano-p-benzoquinone (DDQ) Conditions for deprotection of benzyl group are applicable for cleavage of the PMB protecting group Amine protection The benzyl group is occasionally used as a protecting group for amines in organic synthesis. Other methods exist. Aqueous potassium carbonate and benzyl halide (BnCl, BnBr) in methanol Benzaldehyde, 6 M HCl and NaBH3CN in methanol Deprotection methods Hydrogenation in the presence of the palladium catalyst See also Benzylamine References External links Aryl groups Protecting groups