Metal ions and complexes in organic reactions. Part XV. Copper-catalysed substitutions of aryl halides by phthalimide ion

Abstract

Potassium phthalimide (0.01 mol) + p-bromobenzonitrile (A) (0-01 mol) or p-bromonitrobenzene (B) (0.01 mol) + catalyst (0.01 mol) in solvent (100 nil), 24 h under nitrogen ArN(C0) ,C,H, Catalyst and solvent Yield (yo) (A) CuI, dimethylacetamide a 94 (A) Cu,O, dimethylacetamide 57 (A) C U ~+ , ~ dimethylacetamide a 55 (A) CuBr,, dimethylacetamide 12 (A) No catalyst, dimethylacetarnide a 8 (A) CuBr, dimethylacetamide a 82 (A) Cu, dimethylacetamide a 15 Temp. Catalyst and solvent ("C) CuI, dimethylacetamide 165 CuI, 2,4,6-collidine b 165 CuI, quinoline b 165 CuI, nitrobenzene 6 165 CuI, diethylene glycol dimethyl 162 Cur, dimethylformamide a 155 CuI, p-xylene 138 CuI, 2-picoline 0 128* For recent discussions of copper-assisted nucleophilic substitutions involving perfluoro-aryl and -alkyl halides see

A phase-matchable nonlinear optical material N-(3-nitrophenyl)phthalimide: Synthesis, crystal growth and characterization

“…It was later purified by recrystallization process. The recorded melting point temperature of N3NP is 246 1C, which finds good agreement with that of literature (244-246 1C) [5,6].…”

Copper Complexes of Anionic Nitrogen Ligands in the Amidation and Imidation of Aryl Halides

“…This observation is counterintuitive, but it is consistent with several pieces of prior data. One set of results showed that the coupling of potassium phthalimide with iodoarenes or bromoarenes, catalyzed by CuBr, occurred faster when a 1:1 ratio of potassium phthalimide to copper was used, although the actual copper species in these systems were not identified 66. More recently, Karlin has shown that three-coordinate Cu(I) complexes undergo air oxidation much faster than linear two-coordinate Cu(I) complexes 67…”

“…Moreover, Yamamoto’s isolated neutral, PPh3-ligated copper amidate and imidate complexes reacted only at high temperatures 21. During studies of related ligandless copper-catalyzed imidation of bromoarenes, Bacon and Karim showed that a 1:1 ratio of copper iodide to phthalimide led to the fastest formation of N -arylphthalimide product, but no copper complexes in this reaction were identified 66. We have now shown clearly by experiments with fully characterized compounds that two-coordinate imidates alone react with haloarenes more slowly than neutral, three-coordinate imidates.…”

Mechanistic Studies on the Copper-Catalyzed N-Arylation of Amides

“…18a In contrast, with studies using phthalimide as the nucleophile, the most reactive species was generated when the Cu(I):pthalimidate ratio was <1, suggesting that an anionic bis-amido Cu(I) species is unfavorable in this case (eq 2). 19 Furthermore, both Whitesides20 and Yamamoto21 have shown that Cu(I) alkoxides and Cu(I) amidates can react with aryl halides when the Cu:nucleophile ratio is 1:1. Importantly, what these studies suggest is that a Cu(I)-nucleophile complex must form prior to aryl halide activation.…”