Copper(I) Iodide-Triethylphosphine-Lithium Naphthalenide1

CuI.Et3P.Li(C10H8)
(LiNaph)

[7308-67-0]  · C10H8Li  · Copper(I) Iodide-Triethylphosphine-Lithium Naphthalenide  · (MW 135.12) (CuI.PEt3)

[56667-47-1]  · C6H15CuIP  · Copper(I) Iodide-Triethylphosphine-Lithium Naphthalenide  · (MW 308.63)

(a zerovalent copper species which adds to organic halides to produce organocopper compounds; used to cross-couple aryl, alkynyl, and vinyl halides with acid chlorides and reactive alkyl halides; to effect conjugate additions to a,b-unsaturated ketones; to promote intramolecular cyclization with epoxide cleavage or of a,o-dihaloalkanes; to remotely functionalize esters)

Solubility: copper species generated in THF, dioxane, glyme, etc.

Form Supplied in: not commercially available; generated in situ.2

Analysis of Reagent Purity: not reported; reactions usually carried out under argon or dry nitrogen.

Handling, Storage, and Precautions: the reagent is generated in an inert atmosphere as needed.

Reactions of Organocopper Reagents.

It is suggested that treatment of Lithium Naphthalenide in THF or glyme under an argon atmosphere with the copper(I) iodide-triethylphosphine complex in THF (or glyme) produces a highly reactive form of zerovalent copper which is subsequently allowed to react with allyl, aryl, and alkyl halides (in the same solvent) to yield homocoupled products (eq 1).2 Alternatively, if two alkyl, aryl, etc. halides are mixed prior to addition to the active copper species, cross-coupling occurs (eq 2).2 A variety of functional groups (e.g. cyano, nitro) is tolerated during the coupling.2

The conjugate addition to 2-cyclohexenone of a variety of alkyl halides, some bearing additional functionality, has also been effected in the presence of CuI.Et3P.Li(C10H8) (eq 3).1

Additionally, a number of epoxides (terminal and otherwise) have been opened both intermolecularly and intramolecularly in the presence of CuI.Et3P.Li(C10H8) (eq 4). The solvent has been shown to play an important role in determining whether an exo-tet or endo-tet process occurs.1,3 Thus for the products shown in eq (4), the ratio of cyclopentylmethanol to cyclohexanol is 1:6 in THF but 1:0 in toluene!1

In the presence of CuI.Et3P.Li(C10H8), dihalides have been induced to undergo intramolecular cyclization (eq 5)4 and esters have been functionalized at remote positions (eq 6).5


1. Rieke, R. D.; Wehmeyer, R. M.; Wu, T.-C.; Ebert, G. W. T 1989, 45, 443.
2. (a) Ebert, G. W.; Rieke, R. D. JOC 1984, 49, 5282. (b) Ebert, G. W.; Rieke, R. D. JOC 1988, 53, 4482.
3. Baldwin, J. CC 1976, 734.
4. Ginah, F. O.; Donovan, T. A.; Suchan, S. D.; Pfennig, D. R.; Ebert, G. W. JOC 1990, 55, 584.
5. Ebert, G. W.; Cheasty, J. W.; Tehrani, S. S.; Aouad, E. OM 1992, 11, 1560.

Serge Jasmin & David R. Dalton

Temple University, Philadelphia, PA, USA



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