Rhodium- and Iridium-Catalyzed Allylation of Electron-Rich Arenes with Allyl Tosylate

Abstract

The allylation of electron-rich arenes with allyl tosylate proceeded at 0 °C in the presence of [Rh(nbd)(CH₃CN)₂]PF₆. Various oxygenated arenes were allylated with high para-selectivity in almost all cases. Especially in the reaction of anisoles, the tendency was remarkable.

Key words

allylations - arenes - catalysis - iridium - rhodium

References

• 1 Natori S. In Natural Products Chemistry   Vol. 2:  Nakanishi K. Goto T. Ito S. Natori S. Nozoe S. Kodansha Scientific; Tokyo: 1975.  p.131 
• 2 Olah GA. Krishnamurti R. Prakash GKS. In Comprehensive Organic Synthesis   Vol. 3:  Trost BM. Pergamon Press; Oxford: 1991.  p.293 
• 3 Roberts RM. Khalaf AA. Friedel-Crafts Alkylation Chemistry, A Century of Discovery   Dekker; New York: 1984. 
• 4 Tsuchimoto T. Tobita K. Hiyama T. Fukuzawa S. Synlett  1996,  557 
• 5 Tada Y. Satake A. Shimizu I. Yamamoto A. Chem. Lett.  1996,  1021 
• 6 Nishibayashi Y. Yamanishi M. Takagi Y. Hidai M. Chem. Commun.  1997,  859 
• 7 Shimizu I. Sakamoto T. Kawaragi S. Maruyama Y. Yamamoto A. Chem. Lett.  1997,  137 
• 8a Malkov AV. Davis SL. Baxendale IR. Michell WL. Ko èovsk P. J. Org. Chem.  1999,  64:  2751 
• 8b Malkov AV. Spoor P. Vinader V. Koè ovsk P. J. Org. Chem.  1999,  64:  5308 
• 9a Tsukada N. Sugawara S. Inoue Y. Org. Lett.  2000,  2:  655 
• 9b Tsukada N. Sato T. Inoue Y. Chem. Commun.  2001,  237 
• 10 The cyclization of 8a catalyzed by TsOH, which generated from the reaction of allyl tosylate and 7. Treatment of 8a with 50 mol% of TsOH˙H₂O for 15 h at room temperature in toluene afforded 8b quantitively
• For reviews, see:
• 12a Wipf P. In Comprehensive Organic Synthesis   Vol. 5:  Trost BM. Fleming I. Paquette LA. Pergamon Press; Oxford, UK: 1991.  p.827 
• 12b Rhoads SJ. Raulins NR. Org. React.  1975,  22:  1 
• 12c Bennett GB. Synthesis  1977,  589 
• 12d Lutz RP. Chem. Rev.  1984,  84:  205 
• For some recent references, see:
• 13a Bernard AM. Cocco MT. Onnis V. Piras PP. Synthesis  1997,  41 
• 13b Ito H. Sato A. Taguchi T. Tetrahedron Lett.  1997,  38:  4815 
• 13c Trost BM. Toste FD. J. Am. Chem. Soc.  1998,  120:  815 
• 13d Sharma GVM. Ilangovan A. Sreennivas P. Mahalingam AK. Synlett  2000,  615 
• 13e See also: Goux C. Massacret M. Lhoste P. Sinou D. Organometallics  1995,  14:  4585 

11

Reactions with cotyl tosylate and 1-methyl-2-propenyl tosylate should provide some information about the mechanism. However, we were not able to prepare 1-methyl-2-propenyl tosylate because of its instability.

14

Typical Procedure: To a suspension of an arene (5.0 mmol) and [Rh(nbd)(CH₃CN)₂]PF₆ (0.025 mmol) in dry toluene (1 mL), allyl tosylate (0.5 mmol) was added at 0 °C under an N₂ atmosphere. After stirring for 15 h or 24 h, the mixture was filtered thorough a plug of silica, followed by washing with diethyl ether (ca. 30 mL). The solvent was removed under reduced pressure to give an oil that was further purified by flash column chromatography to yield an allylated product. The products obtained were identified by comparison of their ¹H NMR spectral data with those of commercial or reported samples.