Rhodium(I)-Catalyzed Enantioselective Cyclization of Enynes through Site-Selective C(sp³)–H Bond Activation Triggered by Formation of Rhodacycle

Abstract

Rhodium(I)-catalyzed enantioselective cyclization of enynes through C(sp³)–H bond activation was investigated. It was found that the cyclization of enynes having a tert-butyl moiety on the alkene afforded a spirocyclic compound (up to 92% ee), while the cyclization of enynes having an isopropyl or an ethyl group on the alkene gave a cyclic diene (up to 98% ee). Furthermore, an intermolecular competition reaction using a deuterium-labeled substrate revealed that C(sp³)–H bond activation was one of the key steps, having a high energy barrier, in this cyclization.

Key words

rhodium - enantioselective cyclization - C(sp³)–H bond activation - alkene - alkyne - enyne

• References


For selected recent reviews, see:
• 1a Gutekunst WR, Baran PS. Chem. Soc. Rev. 2011; 40: 1976
• 1b McMurray LF, O’Hara L, Gaunt M. Chem. Soc. Rev. 2011; 40: 1885
• 1c Wencel-Delord J, Glorius F. Nat. Chem. 2013; 5: 369
• 1d Yamaguchi J, Yamaguchi AD, Itami K. Angew. Chem. Int. Ed. 2012; 51: 8960
• 1e Hartwig JF. J. Am. Chem. Soc. 2016; 138: 2
• 1f Davies HM. L, Morton DJ. J. Org. Chem. 2016; 81: 343
• 1g Saint-Denis TG, Zhu R.-Y, Chen G, Wu Q.-F, Yu J.-Q. cience 2018; 359: 747
• 2 Oonishi Y, Kitano Y, Sato Y. Angew. Chem. Int. Ed. 2012; 51: 7305
• 3 For an example of Rh(I)-catalyzed cyclization through C(sp³)–H bond activation triggered by formation of rhodacycle, see: Mukai C, Ohta Y, Oura Y, Kawaguchi Y, Inagaki F. J. Am. Chem. Soc. 2012; 134: 19580 

For selected examples of Rh(I)-catalyzed cyclization through C(sp²)–H bond activation triggered by formation of rhodacycle, see:
• 4a Tanaka K, Otake Y, Wada A, Noguchi K, Hirano M. Org. Lett. 2007; 9: 2203
• 4b Tsuchikama K, Kuwata Y, Tahara Y, Yoshinami Y, Shibata T. Org. Lett. 2007; 9: 3097
• 4c Tanaka K, Otake Y, Sagae H, Noguchi K, Hirano M. Angew. Chem. Int. Ed. 2008; 47: 1312
• 4d Kawaguchi Y, Yasuda S, Kaneko A, Oura Y, Mukai C. Angew. Chem. Int. Ed. 2014; 53: 7608
• 4e Kawaguchi Y, Yasuda S, Mukai C. Angew. Chem. Int. Ed. 2016; 55: 10473
• 4f Kawaguchi Y, Yasuda S, Mukai C. J. Org. Chem. 2017; 82: 7666

For selected examples of Rh(I)-catalyzed enantioselective cycloisomerization of enynes through oxidative cyclization, see:
• 5a Cao P, Wang B, Zhang X.-M. J. Am. Chem. Soc. 2000; 122: 6490
• 5b Lei A, He M, Zhang X. J. Am. Chem. Soc. 2002; 124: 8198
• 5c Mikami K, Yusa Y, Hatano M, Wakabayashi K, Aikawa K. Tetrahedron 2004; 60: 4475
• 5d Nicolaou KC, Li A, Ellery SP, Edmonds DJ. Angew. Chem. Int. Ed. 2009; 48: 6293
• 5e Masutomi K, Noguchi K, Tanaka K. J. Am. Chem. Soc. 2014; 136: 7627
• 5f Deng X, Ni S.-F, Han Z.-Y, Guan Y.-Q, Lv H, Dang L, Zhang X.-M. Angew. Chem. Int. Ed. 2016; 55: 6295

For an example of Rh(I)-catalyzed enantioselective Pauson–Khand-Type reaction of enynes through oxidative cyclization, see:
• 5g Jeong N, Sung BK, Choi YK. J. Am. Chem. Soc. 2000; 122: 6771

For selected examples of Rh(I)-catalyzed enantioselective [2+2+2] cycloaddition of enynes through oxidative cyclization, see:
• 5h Shibata T, Arai Y, Tahara Y. Org. Lett. 2005; 7: 4955
• 5i Evans PA, Lai KW, Sawyer JR. J. Am. Chem. Soc. 2005; 127: 12466
• 5j Shibata T, Tahara Y. J. Am. Chem. Soc. 2006; 128: 11766
• 5k Shibata T, Tahara Y, Tamura K, Endo K. J. Am. Chem. Soc. 2008; 130: 3451
• 5l Ishida M, Shibata Y, Noguchi K, Tanaka K. Chem. Eur. J. 2011; 17: 12578
• 5m Suda T, Noguchi K, Tanaka K. Angew. Chem. Int. Ed. 2011; 50: 4475
• 5n Masutomi K, Sakiyama N, Noguchi K, Tanaka K. Angew. Chem. Int. Ed. 2012; 51: 13031
• 5o Yoshizaki S, Nakamura Y, Masutomi K, Yoshida T, Noguchi K, Shibata Y, Tanaka K. Org. Lett. 2016; 18: 388
• 5p Masutomi K, Sugiyama H, Uekusa H, Shibata Y, Tanaka K. Angew. Chem. Int. Ed. 2016; 55: 15373
• 5q Ueda H, Masutomi K, Shibata Y, Tanaka K. Org. Lett. 2017; 19: 2913
• 5r See also ref. 4c

For our recent studies on Rh(I)-catalyzed cyclization through oxidative addition of two C–C multiple bonds, see:
• 6a Oonishi Y, Kitano Y, Sato Y. Tetrahedron 2013; 69: 7713
• 6b Oonishi Y, Yokoe T, Hosotani A, Sato Y. Angew. Chem. Int. Ed. 2014; 53: 1135
• 6c Oonishi Y, Hato Y, Sato Y. Adv. Synth. Catal. 2015; 357: 3033
• 6d Oonishi Y, Hato Y, Sato Y. Adv. Synth. Catal. 2016; 358: 2273
• 6e Hato Y, Oonishi Y, Yamamoto Y, Nakajima K, Sato Y. J. Org. Chem. 2016; 81: 7847
• 7 For our recent study on Rh(I)-catalyzed asymmetric cyclization of enyne through O–H bond activation, which was triggered by the formation of the rhodacycle, see: Oonishi Y, Masusaki S, Sakamoto S, Sato Y. Angew. Chem. Int. Ed. 2019; 58: 8736
• 8 The geometry of alkene in the cyclic compound 4a was determined by NOESY. The absolute configuration of 4a and 5a was not determined.
• 9 Compound 4a was subjected to the standard reaction conditions, giving 5a in 80% yield (Scheme 7).

For selected examples of the cyclizations with the formation of 4-membered carbocyclic compound through C(sp³)–H bond activation, see:
• 10a Chaumontet M, Piccardi R, Audic N, Hitce J, Peglion J.-L, Clot E, Baudoin O. J. Am. Chem. Soc. 2008; 130: 15157
• 10b Rousseaux S, Davi M, Sofack-Kreutzer J, Pierre C, Kefalidis CE, Clot E, Fagnou K, Baudoin O. J. Am. Chem. Soc. 2010; 132: 10706
• 10c Kefalidis CE, Davi M, Holstein PM, Clot E, Baudoin O. J. Org. Chem. 2014; 79: 11903
• 11 The effect of the counter anion (X) of a cationic Rh(I) complex on the reactivity was investigated using a [Rh(cod)₂]X (X = ClO₄, PF₆, SbF₆, and BAr^F ₄). However, these anions showed almost the same reactivity as those using BF₄ in this cyclization.
• 12 Huang studied the mechanism for Rh(I)-catalyzed cyclization of allenyne through C(sp³)–H bond activation (ref. 2) by means of DFT calculation. According to this work, the cyclization proceeded through metal-assisted σ-bond metathesis like rhoda­cycle iv, see: Huang G. Org. Lett. 2015; 17: 1994

For recent reviews, see:
• 13a Gómez-Gallego M, Sierra MA. Chem. Rev. 2011; 111: 4857
• 13b Simmons EM, Hartwig JF. Angew. Chem. Int. Ed. 2012; 51: 3066