Lithium Bis(N-methyl-N-phenylcarbamoyl)cuprate

[85138-79-0]  · C16H16CuLiN2O2  · Lithium Bis(N-methyl-N-phenylcarbamoyl)cuprate  · (MW 338.80)

(carbamoylation of organic halides1)

Alternate Name: lithium bis[(methylphenylamino)carbonyl]cuprate.

Preparative Method: prepared in situ: a solution of 18.7 mmol of N-methylaniline in 45 mL of anhyd ether was placed in a reaction flask equipped with a balloon; n-Butyllithium in hexane (12 mL of a 15% solution) was added with stirring at 0 °C; the resulting pale yellow solution was stirred for 1 h and exposed to Carbon Monoxide for 0.5 h at 0 °C to inactivate excess n-BuLi; a homogeneous solution was formed after adding 9.35 mmol of purified Copper(I) Iodide at 0 °C; after reaction with CO at 0 °C for 3.5 h, the reagent formed as a white precipitate.1

Handling, Storage, and Precautions: air- and moisture-sensitive; handle under dry N2; irritant; the hazards of CO are well-documented.2


This reagent behaves very similarly to Lithium Bis(N,N-diethylcarbamoyl)cuprate, a carbamoylation reagent reactive towards organic halides.1,3,4 The reaction with Benzyl Bromide and iodobenzene gave carbamoylation products (5) and (6) in low yield (eq 1). N,N-Dimethyl-N,N-diphenylethanediamide (7), formed as a byproduct, proved to be an oxidative dimerization product arising from the organic group in the CO-containing copper complex. Reaction with N-Bromosuccinimide gave N,N-dimethylcarbanilide in 46% yield. The similar reaction with 1,2-epoxyethylbenzene gave the expected 3-hydroxy-N-methyl-N-phenyl-3-phenylpropanamide (10) in 52% yield.1

The reaction with iodobenzene could be optimized under the catalysis of palladium; otherwise, the yield was less than 5% (eq 2).1,3

Conversion to Oxamide and Carbamate Derivatives.

Like lithium bis(N,N-diethylcarbamoyl)cuprate, lithium bis(N-methyl-N-phenylcarbamoyl)cuprate can also be converted to the corresponding oxamide by treatment with Bromine or Titanium(IV) Chloride (eq 3).3 Formation of the corresponding oxamic acid was accomplished by reaction with Carbon Dioxide and warming with dilute acid (eq 4). Its carbamate was produced on treatment with bromine and then with Sodium Methoxide in methanol (eq 5).3

1. Wakita, Y.; Kobayashi, T.; Maeda, M.; Kojima, M. CPB 1982, 30, 3395.
2. See, for example, (a) Sax, N. I.; Lewis, R. J. Dangerous Properties of Industrial Materials, 7th ed.; Van Nostrand Reinhold: New York, 1989; Vol. 2, p 713. (b) The Sigma-Aldrich Library of Chemical Safety Data, 2nd ed.; Lenga, R. E., Ed.; Sigma-Aldrich: Milwaukee, 1988; Vol. 1, p 685.
3. Wakita, Y.; Noma, S.-Y.; Maeda, M.; Kojima, M. JOM 1985, 297, 379.
4. Tsuda, T.; Miwa, M.; Saegusa, T. JOC 1979, 44, 3734.

Edward J. Parish & Shengrong Li

Auburn University, AL, USA

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