*[-]*
· C_{3}H_{5}Li_{2}NO_{2}
· *O,O*-Dilithio-1-nitropropene
· (MW 100.96)

(reacts with electrophiles at the b-position; electrophiles may be alkyl halides, aldehydes, ketones, a,b-unsaturated aldehydes and ketones, esters, and nitroalkenes^{1-10})

*Alternate Name:* *N,N*-[bis(lithioxy)]-1-propenylamine.

*Preparative Methods:* generated by a,b-double deprotonation of nitroalkanes with BuLi or LDA.

Treatment of nitroalkanes with excess strong base may lead to a,a- or a,b-double deprotonation (eq 1). With simple nitroalkanes (**2**) (R = H or alkyl) the isomeric dilithio derivatives (**1**) and (**3**) can be generated selectively by reversing the mode of addition of the reagents. The lithium lithionitronate (**3**) is formed when 2 equiv **n-Butyllithium** are added to a solution of the nitroalkane in THF/HMPA or

The chemistry of doubly lithiated methyl 3-nitropropanoate (**1**) (R = CO_{2}Me) is covered in the article on ** Methyl 3-Nitropropanoate**. The reagents (

An example of the preparation of a homo-nitroaldol from a simple nitropropane is shown in eq 4.^{10} The nitroalcohol (**5**) is isolated in 77% yield, with essentially no isomeric ordinary nitroaldol being formed; the diastereomer ratio (dr) is poor (2.6:1).

More complex nitroalcohols of this type are produced when nitrocyclopentane and nitrocyclohexane are doubly lithiated and added to benzaldehydes to give (**6**) (40% yield, dr = 4:1) and (**7**) (32% yield, dr > 20:1),^{8} or when 1,1,1-trifluoro-2-nitropropane is employed (see (**8**) in eq 5) (20% yield, dr = 3:1).^{9} A special demonstration of the reactivity umpolung is the preparation of an unsymmetrical 2,3-diaryl-1,4-dinitrobutane (**9**) from 2-phenylnitroethane and a 2-arylnitroethylene (65% yield) (eq 6).^{5}

Finally, in eq 7 the reactivity of the butadiene derivative (**10**) is outlined; from the bright red solutions of this reagent and electrophiles the isomeric 2-vinylnitroalkanes and 1-nitro-2-alkenes are obtained in varying ratios.^{4} Remarkably, only the regioisomer resulting from reaction at the 4-position is formed in the Michael addition to cyclic (five- through seven-membered ring) and open-chain a,b-enones.^{4,14} The product (**11**), isolated in ~50% yield with cyclohexenone, has been converted to the 1,7-dicarbonyl derivative (**12**) by Nef reaction^{4,14} carried out under the McMurry conditions.^{15}

** Lithium a-Lithiomethanenitronate**;

- 1. (a) Seebach, D.; Colvin, E. W.; Lehr, F.; Weller, T. C.
*C***1979**,*33*, 1. (b) Döpp, D.; Döpp, H.*MOC***1990**,*E14b*, 780. (c) Seebach, D. Pohmakotr, M.*T***1981**,*37*, 4047. (d) Thompson, C. M.; Green, D. L. C.*T***1991**,*47*, 4223. (e) Ono, N. In*Nitro Chemistry*; Feuer, H.; Nielsen A. T., Eds.; VCH: New York, 1990; Chapter 1. (f) Wade, P. A.; Giuliano, R. M. In*Nitro Chemistry*; Feuer, H.; Nielsen, A. T., Eds.; VCH: New York, 1990; Chapter 2. - 2. Henning, R.; Lehr, F.; Seebach, D.
*HCA***1976**,*59*, 2213 (*CA***1976**,*85*, 176 754t). - 3. Seebach, D.; Henning, R.; Lehr, F.; Gonnermann, J.
*TL***1977**, 1161. - 4. Seebach, D.; Henning, R.; Lehr, F.
*AG(E)***1978**,*17*, 458. - 5. Seebach, D.; Henning, R.; Gonnermann, J.
*CB***1979**,*112*, 234 (*CA***1979**,*91*, 19 168m). - 6. Mukhopadhyay, T.; Seebach, D.
*HCA***1982**,*65*, 385. - 7. Seebach, D.; Henning, R.; Mukhopadhyay, T.
*CB***1982**,*115*, 1705. - 8. Brändli, U.; Eyer, M.; Seebach, D.
*CB***1986**,*119*, 575. - 9. Beck, A. K.; Seebach, D.
*CB***1991**,*124*, 2897 (*CA***1992**,*116*, 40 553c). - 10. (a) Yamada, K.; Tanaka, S.; Kohmoto, S.; Yamamoto, M.
*CC***1989**, 110. (b) Tanaka, S.; Kohmoto, S.; Yamamoto, M.; Yamada, K.*NKK***1989**, 1742 (*CA***1990**,*112*, 178 190f). - 11. Seebach, D.; Lehr, F.
*HCA***1979**,*62*, 2239 (*CA***1980**,*92*, 75 654z). - 12. Bossler, H. G.; Seebach, D.
*HCA***1994**,*77*, 1124. - 13. Seebach, D.
*AG(E)***1979**,*18*, 239. - 14. For further examples and details, see: Henning, R. Dissertation, Universität Giessen, 1978.
- 15. Ho, T. L.; Wong, C. M.
*S***1974**, 196.

Roger E. Marti & Dieter Seebach

*Eidgenössische Technische Hochschule, Zürich, Switzerland*

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