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Regioselective Heck Reaction of N ‐Vinylphthalimide: A General Strategy for the Synthesis of ( E )‐ N‐ Styrylphthalimides and Phenethylamines
Author(s) -
Alacid Emilio,
Nájera Carmen
Publication year - 2008
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.200800074
Subject(s) - chemistry , regioselectivity , palladium , catalysis , oxime , phosphine , phenethylamines , medicinal chemistry , aryl , base (topology) , organic chemistry , heck reaction , combinatorial chemistry , stereochemistry , mathematical analysis , alkyl , mathematics
The arylation of N ‐vinylphthalimide takes place at the β‐position with aryl iodides, bromides and chlorides using palladium acetate [Pd(OAc) 2 ] or phenone oxime‐derived palladacycles as catalysts under phosphine‐free conditions. The reaction is succesfully carried out in organic solvents, such as DMF, in the presence of an organic base, such as dicyclohexylmethylamine, and with TBAB as additive at 120 °C under conventional or microwave heating. ( E )‐ N ‐Styrylphthalimides are mainly obtained using a rather low palladium loading (0.05–1 mol%). Similar catalytic efficiency is observed using a Kaiser oxime resin‐derived palladacycle, which allows reuse of the polymeric complex for three cycles. The high regioselectivity observed supports that these palladacycles work as a source of Pd(0) species operating mainly through a neutral mechanism. The syntheses of 2‐thienylphenethylamine and mescaline have been performed by subsequent hydrogenation with Wilkinson’s catalyst and hydrazinolysis.