Lithium Di-(E)-1-propenylcuprate1

[33462-38-3]  · C6H10CuLi  · Lithium Di-(E)-1-propenylcuprate  · (MW 152.65)

(propenylating reagent; undergoes conjugate addition reactions,2 -4 1,2-addition reactions to aldehydes,5,6 substitution reactions with alkyl7 and vinyl substrates,8 and oxidative dimerization9)

Physical Data: colorless solution in Et2O with CuI;7 ink-blue color with CuI.P(OMe)3.4

Solubility: sol Et2O, THF.

Preparative Methods: prepared in situ from CuI salts (Copper(I) Iodide)7 or complexes (Copper(I) Iodide-Tributylphosphine5,9 and Copper(I) Iodide-Trimethyl Phosphite4) in Et2O or THF at -78 °C under argon1c by the addition of trans-1-propenyllithium.7 See Lithium Dimethylcuprate for purification of CuI salts.

Handling, Storage, and Precautions: air- and moisture-sensitive; use in a fume hood.


Lithium di-(E)-1-propenylcuprate displays the typical reactivity patterns of lithium diorganocuprates (see Lithium Dimethylcuprate).

Addition Reactions.

Lithium di-(E)-1-propenylcuprate undergoes 1,4-addition to simple a,b-alkenyl ketones2 with retention of alkene configuration by conjugate transfer of the (E)-1- propenyl ligand. This reaction has been applied to the synthesis of (±)-dechloromycorrhizin A (eq 1).10 1,4-Additions have been achieved with ethyl acrylate and ethyl propiolate in limited yields.4 In the synthesis of aucantene, 1,4-addition to an a,b-alkenyl aldehyde3 was achieved (eq 2). Diastereoselective 1,2-additions of lithium di-(E)-1-propenylcuprate to aldehydes can be performed in good yields5 and in the presence of Magnesium Bromide etherate, which facilitates chelation control (eq 3).6

Substitution Reactions.

Lithium di-(E)-1-propenylcuprate reacts with alkyl halides and tosylates in high-yield substitution reactions, with and without HMPA additive, in Et2O or THF.7 Coupling of lithium di-(E)-1-propenylcuprate with a vinyl chloride was used in the synthesis of fulvoplumieren (eq 4).8

Oxidation Reactions.

Oxidative dimerization of a copper(I) ate complex prepared from trans-1-propenyllithium affords a good yield of the dimer trans,trans-2,4-hexadiene, without loss of stereochemical integrity (eq 5).9

Related Reagents.

Lithium Diallylcuprate; Lithium Bis(1-ethoxyvinyl)cuprate; Lithium Diisopropenylcuprate; Lithium Bis(1-methoxyvinyl)cuprate; Lithium Divinylcuprate; Lithium Divinylcuprate-Tributylphosphine.

1. (a) Posner, G. H. OR 1972, 19, 1. (b) Posner, G. H. OR 1975, 22, 253. (c) Faust, J.; Froböse, R. In Gmelin Handbook of Inorganic Chemistry; Springer-Verlag: Berlin, 1983; Copper, Part 2. (d) Lipshutz, B. H.; Sengupta, S. OR 1992, 41, 135.
2. Casey, P. C.; Boggs, R. A. TL 1971, 2455.
3. Liu, H.-J.; Browne, E. N. C. CJC 1978, 56, 306.
4. Näf, F.; Degen, P. HCA 1971, 54, 1939.
5. Burke, S. D.; Armistead, D. M.; Fevig, J. M. TL 1985, 26, 1163.
6. Kallmerten, J.; Balestra, M. JOC 1986, 51, 2855.
7. Linstrumelle, G.; Krieger, J. K.; Whitesides, G. M. OS 1976, 55, 103; also see OSC 1988, 6, 1040.
8. Büchi, G.; Carlson, J. A. JACS 1969, 91, 6470.
9. Whitesides, G. M.; San Filippo, J., Jr.; Casey, C. P.; Panek, E. J. JACS 1967, 89, 5302.
10. Koft, E. R.; Smith, A. B., III JACS 1982, 104, 2659.

Christopher W. Alexander & R. Karl Dieter

Clemson University, SC, USA

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