[71092-51-8]  · C8H16Sn  · 2-Trimethylstannylmethyl-1,3-butadiene  · (MW 230.95)

(isoprenylation reagent;1 Diels-Alder diene1)

Physical Data: bp 77-78 °C/40 mmHg.

Analysis of Reagent Purity: 1H NMR d 0.07 (9H, s), 1.89 (2H, d, J = 1.0 Hz), 4.65-5.20 (4H, m), 6.33 (1H, dd, J = 10.0, J = 17.4 Hz); lmax (hexane) 239.5 (ε 10 000).

Solubility: sol common organic solvents but avoid hydroxylic solvents.

Purification: by distillation.

Preparative Methods: by the reaction of the Grignard reagent prepared from chloromethyltrimethylstannane and chloroprene in the presence of a catalytic amount of dichlorobis(diphenylphosphino)propanenickel(II) in 75% yield,2 analogous to the procedure employed for the preparation of 2-Trimethylsilylmethyl-1,3-butadiene.3 The reaction of Trimethylstannyllithium4 with a-bromoisoprene5 also gives 2-trimethylstannylmethyl-1,3-butadiene in 70% yield.6

Handling, Storage, and Precautions: can be stored in a glass bottle under nitrogen. Organotin derivatives are known to be toxic. Therefore the reagents should be handled in a well-ventilated hood and contact with the skin and eyes should be avoided.

Diels-Alder Reaction.

2-Trimethylstannylmethyl-1,3-butadiene undergoes Diels-Alder reactions with a variety of dienophiles in high yield (eqs 1 and 2). With unsymmetrical dienophiles, the para products are obtained with higher selectivity than the reaction of the silicon analog (see 2-Trimethylsilylmethyl-1,3-butadiene).2

Allylation Reaction.

2-Trimethylstannylmethyl-1,3-butadiene enters the usual allylation reactions with carbonyl compounds in the presence of Boron Trifluoride Etherate (eq 3).7

Cross-Coupling Reaction.

Zinc Chloride-catalyzed reaction with Allyl Bromide results in the formation of allyl coupling products (eq 4).

1. (a) Sakurai, H. PAC 1982, 54, 1. (b) Sakurai, H.; Hosomi, A.; Saito, M.; Sasaki, K.; Iguchi, H.; Sasaki, J.; Araki, Y. T 1983, 39, 883.
2. Hosomi, A.; Saito, M.; Sakurai, H. TL 1980, 21, 355.
3. Hosomi, A.; Saito, M.; Sakurai, H. TL 1979, 429.
4. Tamborski, C.; Ford, F. E.; Soloski, E. JOC 1963, 28, 237.
5. Hegedus, L. S.; Varaprath, S. OM 1982, 1, 259.
6. Godschalx, J. P.; Stille, J. K. TL 1983, 24, 1905.
7. Hosomi, A.; Iguchi, H.; Endo, M.; Sakurai, H. CL 1979, 977.

Hideki Sakurai

Tohoku University, Sendai, Japan

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