P₂O₅ / SiO₂ as a mild and efficient reagent for acylation of alcohols, phenols and amines under solvent-free conditions

Abstract

P 2 O 5 / SiO 2 is a highly efficient reagent for the acetylations of a variety of alcohols, phenols and amines with acetic anhydride under solvent-free conditions. Primary, secondary, allylic and benzylic alcohols, diols and phenols with electron-donating or withdrawing substituents can be easily acetylated in good to excellent yield.

“Traditional” Sol-Gel Chemistry as a Powerful Tool for the Preparation of Supported Metal and Metal Oxide Catalysts

“…Silica supported phosphoric acid was used as a solid acid catalyst for olefin oligomerization and hydration [62,63]. Silica-supported phosphorus pentoxide (P 2 O 5 /SiO 2 ) was used in several transformations, such as oxidation of sulfides to the corresponding sulfoxides [64], the nitration of aromatic compounds [65], synthesis of nitriles from aldehydes [66], and acylation of amines [67].…”

Iron‐Doped Single‐Walled Carbon Nanotubes as New Heterogeneous and Highly Efficient Catalyst for Acylation of Alcohols, Phenols, Carboxylic Acids and Amines under Solvent‐Free Conditions

“…The following compounds obtained in this paper are known compounds: 2‐bromophenyl acetate8k ( 1 ), 2‐methoxyphenyl acetate18 ( 2 ), 2‐nitrophenyl acetate19 ( 3 ), 2,4‐dimethylphenyl acetate20 ( 4 ), 3‐tolyl acetate21 ( 5 ), 3,5‐dimethylphenyl acetate22 ( 6 ), 3‐fluorophenyl acetate23 ( 7 ), 4‐benzylphenyl acetate24 ( 8 ), 4‐bromophenyl acetate25a ( 9 ), 4‐chlorophenyl acetate25b ( 10 ), 4‐ tert ‐butylphenyl acetate8i ( 11 ), 4‐nitrophenyl acetate26 ( 12 ), naphthalen‐1‐yl acetate6e ( 13 ), naphthalen‐2‐yl acetate27 ( 14 ), phenyl acetate6e ( 15 ), 8‐hydroxy‐9,10‐dioxo‐9,10‐dihydroanthracen‐1‐yl acetate28 ( 16 ), 4‐methoxyphenyl acetate29 ( 17 ), (4‐chlorophenyl)(diethoxyphosphoryl)methyl acetate30a ( 18 ), (diethoxyphosphoryl)( p ‐tolyl)methyl acetate30a ( 19 ), (diethoxyphosphoryl)( m ‐tolyl)methyl acetate30a ( 20 ), (diethoxyphosphoryl)(phenyl)methyl acetate30a ( 21 ), acetic acid 10,13‐dimethyl‐17‐octyl‐2,3,4,7,8,9,10,11,12,13,14,15,16,17‐tetradecahydro‐1 H ‐cyclopenta[ a ]phenanthren‐3‐yl ester31 ( 22 ), acetic acid 2‐oxo‐1,2‐diphenylethyl ester30b ( 23 ), (1 R ,2 R ,5 R )‐2‐isopropyl‐5‐methylcyclohexyl acetate32 ( 24 ), 1‐phenylethyl acetate33 ( 25 ), benzyl acetate32 ( 26 ), 2‐nitrobenzyl acetate34 ( 27 ), acetic acid dodecyl ester35 ( 28 ), 2‐methyl‐1‐phenylpropan‐2‐yl acetate32 ( 29 ), 4‐methoxyphenyl benzoate36 ( 30 ), 4‐chlorophenyl benzoate36 ( 31 ), dodecyl benzoate37 ( 32 ), 4‐methoxyphenyl 2‐chlorobenzoate38 ( 33 ), 4‐methoxyphenyl 2‐phenylacetate39 ( 34 ), 4‐methoxyphenyl 4‐methylbenzoate40 ( 35 ), phenyl 2‐chloroacetate41 ( 36 ), 4‐methoxyphenyl thiophene‐2‐carboxylate42 ( 37 ), 3,6,9,12‐tetraoxa‐18‐azabicyclo[12.3.1]octadeca‐1(18),14,16‐triene‐2,13‐dione43 ( 38 ), N ‐phenylacetamide26 ( 39 ), N ‐(2‐cyanophenyl)acetamide44 ( 40 ), N ‐(4‐bromophenyl)acetamide43 ( 41 ), N ‐(4‐nitrophenyl)acetamide26 ( 42 ), N ‐(4‐cyanophenyl)acetamide45 ( 43 ), N ‐(2‐chlorophenyl)acetamide46 ( 44 ), N ‐(3‐hydroxyphenyl)acetamide47a ( 45 ), N ‐(4‐acetylphenyl)acetamide47b ( 46 ), 2‐acetamidobenzoic acid48 ( 47 ), 5‐acetamido‐2‐hydroxybenzoic acid49 ( 48 ), N ‐(3‐bromophenyl)acetamide50 ( 49 ), N‐o ‐tolylacetamide…”

Phosphorus Pentoxide

“…Primary, secondary, allylic and benzylic alcohols, diols and phenols with electron-donating or -withdrawing substituents can be easily acetylated in high yield. 5 In addition, it is used to synthesize phosphorus compounds 6 and polymers. 7…”

“…Primary, secondary, allylic and benzylic alcohols, diols and phenols with electron-donating or -withdrawing substituents can be easily acetylated in high yield. 5 In addition, it is used to synthesize phosphorus compounds 6 and polymers. (A) New types of concerted domino acylation-cycloalkylation reactions promoted by methanesulfonic acid-phosphorus pentoxide, provide efficient, elegant, and expeditious routes for biologically active naturally occurring diterpenoids, namely (±)-ferruginol (3a), (±)-nimbidiol (3b), (±)-nimbiol (3c) (75-90%).…”