[6651-43-0]  · C7H14OSi  · 1-Trimethylsilyloxy-1,3-butadiene  · (MW 142.30)

(easily prepared1 reactive diene for Diels-Alder reactions and other cycloadditions;2-21 reactive silyl enol ether for aldol and Michael reactions,22-28 and electrophilic additions29-32)

Physical Data: bp 131 °C, bp 49.5 °C/25 mmHg; d 0.811 g cm-3.

Solubility: sol most standard organic solvents.

Form Supplied in: liquid commercially available (98% purity) as an approximately 85:15 mixture of (E)- and (Z)-isomers.

Preparative Methods: can be prepared easily.1

Handling, Storage, and Precautions: is a flammable liquid and is moisture sensitive.

Diels-Alder Reactions and Other Cycloadditions.

Although commercially available, 1-trimethylsilyloxy-1,3-butadiene (1) can be easily prepared by silylation of Crotonaldehyde.1 It has often been used as a reactive diene in Diels-Alder reactions. For example, reaction with Dimethyl Acetylenedicarboxylate (2) affords the cyclohexadiene diester (3) in 68% yield. This initial Diels-Alder adduct can be converted into two different aromatic products by the proper choice of conditions: namely, thermal elimination affords the phthalate (4), while oxidation produces the phenol (5), both in good yield (eq 1).2 Reaction with Methyl 3-Nitroacrylate (6) followed by hydrolysis of the initial adduct (7) and elimination of the b-nitro group leads to the cyclohexadienol (8) (eq 2).3 Many other Diels-Alder reactions of this type have been carried out using (1), as shown in Table 1.4 In general, the endo adduct is favored, especially at lower temperatures.

Cyclic enones, lactones, and lactams have also been used often as dienophiles in Diels-Alder reactions with (1), again giving mainly the endo adduct,5 e.g. (12) reacted with (1) to give (13) as the major product in 74% yield (eq 3).5a As mentioned earlier, the initial adducts are often oxidized (either directly or after hydrolysis of the silyl ether) with Jones reagent to the corresponding enone,6 e.g. (14) to give (15) (eq 4).6a This corresponds to the annulation of a cyclohexenone unit onto an existing enone or unsaturated lactone unit and has been used often in synthesis, e.g. in the preparation of aureolic acid derivatives such as (17) from (16) and (1) (eq 5).6c

There are some exceptions to the preference for endo stereochemistry, especially with unsaturated sulfones.7 A curious and useful reversal of the stereochemical preference has been reported, namely Diels-Alder cycloaddition of the pyrazolecarboxylate (18) with (1) followed by photochemical elimination of nitrogen gave mainly the endo adduct (19n) (eq 6), whereas cycloaddition of (1) with the cyclopropenecarboxylate (20) gave nearly exclusively the exo adduct (19x) (eq 7).8

Stereocontrol with acyclic dienophiles can also be high,9 e.g. (21) giving only (22) (eq 8),9a although the relative stereochemistry of the adjacent allylic center can cause nearly stereorandom addition as well.9a The versatility of the initial adducts has been evidenced most clearly in the synthesis of anthraquinones and their derivatives. The adducts of (1) with various quinones and substituted quinones have been transformed into simple aromatics,10 phenols,11 e.g. (23) gave (24) (eq 9),11a cyclohexenones,12 e.g. (25) gave (26) (eq 10),12a and allylic alcohols,13 all in excellent yields.

The reaction can be carried out with excellent enantiocontrol (generally 80% or better) using juglone (27) and a catalyst prepared from Trimethyl Borate and a tartaramide to give (28) (eq 11).13a Finally, with metal complexes of tropene and tropone systems, one can obtain either normal [4 + 2] cycloadditions14a or novel [6 + 4] cycloadditions, e.g. (29) giving (30) (eq 12).14b,c Other [4 + 2] cycloadditions have also been reported, using as dienophiles aldehydes15 to give pyran derivatives such as (31), vinyl chlorides,16 singlet oxygen,17 nitrosoalkanes18 to give compounds such as (32), and phosphaalkenes (eq 13).19 Several [2 + 2] cyclizations are known, namely carbene and ketene additions to (1), all of which occur at the unsubstituted double bond.20 One clever use of (1) in synthesis is the tandem [2 + 2]-Cope process which converts (33) into (34) (eq 14).20d Finally, a nickel(0)-catalyzed [4 + 4] cyclization of (1) gives the trans-3,4-bis(silyloxy)-1,5-cyclooctadiene (35) in excellent yield (eq 15).21

Aldol Condensations.

The nucleophilicity of the g-carbon atom in 1-trimethylsilyloxy-1,3-butadiene (1) allows Lewis acid-catalyzed aldol condensations to be carried out, with (1) acting as the equivalent of the enolate of crotonaldehyde.22-26 The products usually have the (E) stereochemistry about the newly formed double bond. Orthoesters are good electrophiles;22,1d when orthoformate is used as the electrophile, the (E)-monoacetal of glutacondialdehyde (36) is formed in good yield.22e This was then used in a very short synthesis of the antiviral agent AZT (37) (eq 16).22e 1,3-Dithienium salts and 2-alkoxydithiolanes have also been used to produce the dithioacetals corresponding to (36).23 Simple acetals and a-chloro ethers can be used as the electrophiles with (1) to generate initially d-alkoxy-a,b-unsaturated aldehydes and then the doubly unsaturated aldehydes after treatment with base.24,1c A clever approach to the synthesis of indole from pyrrole involves the condensation of (1) with the endoperoxides derived from N-alkoxycarbonylpyrrole as shown in eq 17.25a An approach to the piperidine alkaloids uses similar chemistry.25b,c

Finally, a conceptually similar reaction involves the addition of (1) to an acyl imminium salt to give an intermediate (38) (eq 18) which was then used in an intramolecular Diels-Alder approach to the heteroyohimboid alkaloids.26 A Michael adduct is formed when (1) is allowed to react with 2,2-bis(phenylsulfonyl)styrene, probably as the result of a Diels-Alder reaction in which the adduct reverses to a zwitterion and internally deprotonates.27 Also the lithium enolate derived from (1) has been added in a Michael fashion to a,b-unsaturated ketones to give, after silylation, the same adducts as the direct Diels-Alder reaction but at much lower temperatures.28

Electrophilic Additions.

Finally, various electrophiles (other than the carbon species in aldol and other condensations) have been added to (1) in good yield, namely: Benzenesulfenyl Chloride,29 Bromine or N-Bromosuccinimide,30 and t-Butyl Hypochlorite.31 There are also several reports of the reaction of (1) with various transition metal electrophiles which generate either a silyloxydiene bound to the metal32 or a crotonaldehyde unit bound to the metal.33

Related Reagents.

1-Acetoxy-1,3-butadiene; 2-Methoxy-1,3-butadiene; 2-Methoxy-3-phenylthio-1,3-butadiene; 1-Methoxy-3-trimethylsilyloxy-1,3-butadiene; 2-Trimethylsilyloxy-1,3-butadiene.

1. (a) Belg. Patent 670 769, 1966 (CA 1966, 65, 5487d). (b) Cazeau, P.; Frainnet, E. BSF(2) 1972, 1658. (c) Ishida, A.; Mukaiyama, T. BCJ 1977, 50, 1161. (d) Makin, S. M.; Kruglikova, R. I.; Popova, T. P.; Chernyshev, A. I. JOU 1982, 18, 834. (e) Makin, S. M.; Kruglikova, R. I.; Shavrygina, O. A.; Chernyshev, A. I.; Popova, T. P.; Tung, N. F. JOU 1982, 18, 250. (f) Cazeau, P.; Duboudin, F.; Moulines, F.; Babot, O.; Dunoguès, J. T 1987, 43, 2089. (g) Iqbal, J.; Khan, M. A. SC 1989, 19, 515.
2. Yamamoto, K.; Suzuki, S.; Tsuji, J. CL 1978, 649.
3. Danishefsky, S. J.; Prisbylla, M. P.; Hiner, S. JACS 1978, 100, 2918.
4. (a) Kurth, M. J.; Brown, E. G.; Hendra, E.; Hope, H. JOC 1985, 50, 1115. (b) Makin, S. M.; Tung, N. F.; Shavrygina, O. A.; Arshava, B. M.; Romanova, I. A. JOU 1983, 19, 640. (c) Kakushima, M.; Scott, D. E. CJC 1979, 57, 1399. (d) Oida, T.; Tanimoto, S.; Sugimoto, T.; Okano, M. S 1980, 131. (e) Padwa, A.; MacDonald, J. G. JOC 1983, 48, 3189. (f) Kraus, G. A.; Thurston, J.; Thomas, P. J.; Jacobson, R. A.; Su, Y. TL 1988, 29, 1879.
5. (a) Koot, W.-J.; Hiemstra, H.; Speckamp, W. N. JOC 1992, 57, 1059. (b) Alonso, D.; Font, J.; Ortuño, R. M.; d'Angelo, J.; Guingant, A.; Bois, C. T 1991, 47, 5895. (c) Tsuda, Y.; Horiguchi, Y.; Sano, T. H 1976, 4, 1355.
6. (a) Ortuño, R. M.; Guingant, A.; d'Angelo, J. TL 1988, 29, 6989. (b) Moriarty, K. J.; Shen, C.-C.; Paquette, L. A. SL 1990, 5, 263. (c) Franck, R. W.; Subramanian, C. S.; John, T. V.; Blount, J. F. TL 1984, 25, 2439. (d) Kallmerten, J. TL 1984, 25, 2843. (e) Card, P. J. JOC 1982, 47, 2169.
7. (a) Cossu, S.; Delogu, G.; De Lucchi, O.; Fabbri, D.; Licini, G. AG(E) 1989, 28, 766. (b) Hayakawa, K.; Nishiyama, H.; Kanematsu, K. JOC 1985, 50, 512.
8. Rigby, J. H.; Kierkus, P. C. JACS 1989, 111, 4125.
9. (a) Casas, R.; Parella, T.; Branchadell, V.; Oliva, A.; Ortuño, R. M. T 1992, 48, 2659. (b) Serrano, J. A.; Cáceres, L. E.; Román, E. JCS(P1) 1992, 941.
10. (a) Echavarren, A.; Prados, P.; Fariña, F. T 1984, 40, 4561. (b) Kraus, G. A.; Molina, M. T.; Walling, J. A. CC 1986, 1568. (c) Lee, J.; Snyder, J. K. JOC 1990, 55, 4995. (d) Lee, J.; Tang, J.; Snyder, J. K. TL 1987, 28, 3427.
11. (a) Laugraud, S.; Guingant, A.; Chassagrand, C.; d'Angelo, J. JOC 1988, 53, 1557. (b) Kraus, G. A.; Chen, L. JOC 1991, 56, 5098. (c) McKenzie, T. C.; Hassen, W.; Macdonald, J. F. TL 1987, 28, 5435. (d) Cameron, D. W.; Feutrill, G. I.; Gibson, C. L.; Read, R. W. TL 1985, 26, 3887.
12. (a) Kraus, G. A.; Walling, J. A. TL 1986, 27, 1873. (b) Laugraud, S.; Guingant, A.; d'Angelo, J. TL 1989, 30, 83.
13. (a) Maruoka, K.; Sakurai, M.; Fujiwara, J.; Yamamoto, H. TL 1986, 27, 4895. (b) Kraus, G. A.; Taschner, M. J. JOC 1980, 45, 1174. (c) Carretero, J. C.; Cuevas, J. C.; Echavarren, A.; Fariña, F.; Prados, P. JCR(S) 1984, 6.
14. (a) Rigby, J. H.; Ogbu, C. O. TL 1990, 31, 3385. (b) Rigby, J. H.; Ateeq, H. S.; Charles, N. R.; Cuisiat, S. V.; Ferguson, M. D.; Henshilwood, J. A.; Krueger, A. C.; Ogbu, C. O.; Short, K. M.; Heeg, M. J. JACS 1993, 115, 1382. (c) Rigby, J. H.; Ateeq, H. S. JACS 1990, 112, 6442.
15. (a) Cervinka, O.; Svatos, A.; Trska, P.; Pech, P. CCC 1990, 55, 230. (b) Achmatowicz, O., Jr.; Bialecka-Florjanczyk, E. T 1990, 46, 5317. (c) Bélanger, J.; Landry, N. L.; Paré, J. R. J.; Jankowski, K. JOC 1982, 47, 3649.
16. (a) South, M. S.; Liebeskind, L. S. JOC 1982, 47, 3815. (b) Seitz, G.; v. Gemmern, R. S 1987, 953.
17. Clennan, E. L.; L'Esperance, R. P. TL 1983, 24, 4291.
18. McClure, K. F.; Danishefsky, S. J. JOC 1991, 56, 850.
19. Märkl, G.; Kallmünzer, A. TL 1989, 30, 5245.
20. (a) Wenkert, E.; Goodwin, T. E.; Ranu, B. C. JOC 1977, 42, 2137. (b) Tomilov, Yu. V.; Kostitsyn, A. B.; Shulishov, E. V.; Nefedov, O. M. S 1990, 246. (c) Brady, W. T.; Lloyd, R. M. JOC 1981, 46, 1322. (d) Cantrell, W. R., Jr.; Davies, H. M. L. JOC 1991, 56, 723.
21. (a) Tenaglia, A.; Brun, P.; Waegele, B. JOM 1985, 285, 343. (b) Brun, P.; Tenaglia, A.; Waegele, B. TL 1983, 24, 385.
22. (a) Makin, S. M.; Raifel'd, Yu. E.; Zil'berg, L. L.; Arshava, B. M. JOU 1984, 20, 189. (b) Akgün, E.; Pindur, U. S 1984, 227. (c) Akgün, E.; Pindur, U. M 1984, 115, 587. (d) Duhamel, L.; Ple, G.; Ramondenc, Y. TL 1989, 30, 7377. (e) Jung, M. E.; Gardiner, J. M. JOC 1991, 56, 2614.
23. (a) Paterson, I.; Price, L. G. TL 1981, 22, 2833. (b) Hatanaka, K.; Tanimoto, S.; Sugimoto, T.; Okano, M. TL 1981, 22, 3243.
24. (a) Makin, S. M.; Kruglikova, R. I.; Popova, T. P. JOU 1982, 18, 1001. (b) Makin, S. M.; Shavrygina, O. A.; Kruglikova, R. I.; Mikerin, I. E.; Tung, N. F.; Ermakova, G. A. JOU 1983, 19, 1994. (c) Makin, S. M.; Dymshakova, G. M.; Granenkina, L. S. JOU 1986, 22, 256. (d) Ishida, A.; Mukaiyama, T. BCJ 1978, 51, 2077. (e) Ishida, A.; Mukaiyama, T. CL 1977, 467. (f) Ibragimov, M. A.; Lazareva, M. I.; Smit, W. A. S 1985, 880.
25. (a) Natsume, M.; Muratake, H. TL 1979, 3477. (b) Natsume, M.; Muratake, H. H 1980, 14, 615. (c) Natsume, M.; Muratake, H. H 1981, 16, 973.
26. Martin, S. A.; Benage, B.; Geraci, L. S.; Hunter, J. E.; Mortimore, M. JACS 1991, 113, 6161.
27. De Lucchi, O.; Fabbri, D.; Lucchini, V. T 1992, 48, 1485.
28. Kraus, G. A.; Sugimoto, H. TL 1977, 3929.
29. Fleming, I.; Goldhill, J.; Paterson, I. TL 1979, 3205.
30. Duhamel, L.; Guillemont, J.; Le Gallic, Y.; Plé, G.; Poirier, J.-M.; Ramondenc, Y.; Chabardes, P. TL 1990, 31, 3129.
31. Decor, J. P. Ger. Patent 2 708 281, 1977 (CA 1977, 87, 200 795w).
32. Tolstikov, G. A.; Miftakhov, M. S.; Menakov, Yu. B.; Lomakina, S. I. ZOB 1976, 46, 2630.
33. (a) Benyunes, S. A.; Day, J. P.; Green, M.; Al-Saadoon, A. W.; Waring, T. L. AG(E) 1990, 29, 1416. (b) Benyunes, S. A.; Green, M.; Grimshire, M. J. OM 1989, 8, 2268.

Michael E. Jung

University of California, Los Angeles, CA, USA

Copyright 1995-2000 by John Wiley & Sons, Ltd. All rights reserved.