Communication Cite This: J. Am. Chem. Soc. 2018, 140, 6203−6207
pubs.acs.org/JACS
Chiral Magnesium Bisphosphate-Catalyzed Asymmetric Double C(sp3)−H Bond Functionalization Based on Sequential Hydride Shift/ Cyclization Process Keiji Mori,*,‡ Ryo Isogai,† Yuto Kamei,§ Masahiro Yamanaka,§ and Takahiko Akiyama*,† †
Department of Chemistry, Faculty of Science, Gakushuin University, Mejiro, Toshima-ku, Tokyo 171-8588, Japan Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan § Department of Chemistry and Research Center for Smart Molecules, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan ‡
S Supporting Information *
functionalization (sequential hydride shift system).8 The sequential [1,n]-[1,5]-hydride shift (n = 4, 6)/cyclization processes realized the highly diastereoselective synthesis of complex polycyclic frameworks, such as bicyclo[3.2.2]nonanes and linear tricyclic compounds. The catalyzed asymmetric variant of the sequential system would be a promising tool for the rapid construction of multisubstituted chiral tricyclic frameworks that would act as lead structures in important biologically active compounds. Nevertheless, to the best of our knowledge, there is no precedent for the catalytic, enantioselective variant of the double C(sp3)−H bond functionalization involving a sequential hydride shift/cyclization process. We wish to report herein an asymmetric double C(sp3)−H bond functionalization catalyzed by chiral magnesium bisphosphate (Figure 1). This reaction consists of two successive
ABSTRACT: Described herein is a chiral magnesium bisphosphate-catalyzed asymmetric double C(sp3)−H bond functionalization triggered by a sequential hydride shift/cyclization process. This reaction consists of stereoselective domino C(sp3)−H bond functionalization: (1) a highly enantio- and diastereoselective C(sp3)−H bond functionalization by chiral magnesium bisphosphate (first [1,5]-hydride shift), and (2) a highly diastereoselective C(sp3)−H bond functionalization by an achiral catalyst (Yb(OTf)3, second [1,5]-hydride shift).
D
irect functionalization of an unreactive C−H bond is a powerful methodology for rapidly accessing useful organic molecules.1 Because of the high synthetic potential of the methodology, extensive efforts have been devoted to the development of new strategies. Recently, the C(sp3)−H bond functionalization mediated by a hydride shift/cyclization process, namely, the “internal redox process”, has attracted much attention because of its unique features (Scheme 1).2 The Scheme 1. C(sp3)−H Functionalization by the Internal Redox Process
Figure 1. Asymmetric double C(sp3)−H bond functionalization via sequential hydride shift processes.
key feature of this transformation is the [1,5]-hydride shift of the C(sp3)−H bond α to the heteroatom. Subsequent 6-endo cyclization to cationic species A affords fused heterocycle 2.3−6 Recent efforts by us7 and other groups3−6 have led to the unveiling of the high synthetic potential of this methodology. Useful skeletons, such as tetrahydroquinolines,3 tetrahydroisoquinolines,4o,7e benzopyrans,4i,7b tetralins, 4h,7c,d spirooxindoles,4n,6n and indanes,7c,f could be constructed by processes involving a [1,n]-hydride shift (n = 4, 5, 6). Quite recently, our group accomplished the application of this strategy to an unprecedented double C(sp3)−H bond © 2018 American Chemical Society
stereoselective C(sp3)−H bond functionalizations: (1) a highly enantio- and diastereoselective C(sp3)−H bond functionalization by chiral magnesium phosphate (first [1,5]-hydride shift), and (2) a highly diastereoselective C(sp3)−H bond functionalization by an achiral catalyst (second [1,5]-hydride shift). The combination of these two stereoselective reactions enabled the Received: March 12, 2018 Published: May 9, 2018 6203
DOI: 10.1021/jacs.8b02761 J. Am. Chem. Soc. 2018, 140, 6203−6207
Communication
Journal of the American Chemical Society highly enantio- and diastereoselective synthesis of fused tricyclic piperidine derivatives. The desired asymmetric double C(sp3)−H bond functionalization was realized by chiral magnesium bisphosphate 3 (Figure 2).9−12 Upon treatment of cinnamylidene malonate 4
Figure 3. Substrate scope.
chemistry was unambiguously established by single-crystal Xray analysis (see CIF file). The above results clearly indicate the involvement of two stereoselective C(sp3)−H bond functionalizations, as shown in Figure 1: (1) a highly enantio- and diastereoselective C(sp3)− H bond functionalization by chiral magnesium bisphosphate (first [1,5]-hydride shift), and (2) a highly diastereoselective C(sp3)−H bond functionalization by Yb(OTf)3 (second [1,5]hydride shift), with the former being the key stereocontrolling step.14 To gain a deeper insight into the stereochemical outcome, we conducted DFT calculations using simplified and realistic models of the first [1,5]-hydride shift/cyclization process (Figure 4).15,16
Figure 2. Excellent stereoselective reaction following a two-step sequence.
with 10 mol% of 3, bearing bulky 2,4,6-tricyclohexylphenyl groups at the 3,3′-positions, in mesitylene at 60 °C for 96 h, the desired sequential reaction proceeded smoothly to give tricyclic piperidine 5 in 74% yield with 87% ee. Although both chemical yield and enantioselectivity were reasonable, diastereoselectivity remained moderate (dr = 4.9:1).13 Determination of the absolute configuration offered an important clue to overcome this drawback. Subjecting p-bromobenzyl analogue 6a to the optimized reaction conditions gave exclusively the single hydride shift/cyclization adduct 7a (83%), without formation of the expected tricyclic piperidine 8a. The diastereomeric ratio could not be determined at this stage because of the broad nature of the 1H NMR spectrum of 7a. The complete suppression of the second hydride shift process was rationalized by the electronic effect: the electron-deficient aryl-substituted N-benzyl group retarded the [1,5]-hydride shift.7d The second hydride shift/cyclization process of 7a proceeded smoothly when 10 mol% of achiral catalyst Yb(OTf)3 was used under slightly modified reaction conditions (in ClCH2CH2Cl at 60 °C for 0.5 h) to furnish 8a in 96% yield. Gratifyingly, both diastereoselectivity (dr = 11.5:1) and enantioselectivity (96% ee) of the major diastereomer were improved significantly. It should be noted that the process starting from 6a with a pbromobenzyl group would be effective for overriding the two disadvantages (requirement of two-step sequence and use of two different (chiral, achiral) catalysts). Having acquired the highly diastereo- and enantioselective double C(sp3)−H bond functionalization protocol, we next examined the substrate scope of the two-pot reaction (Figure 3). Neither electron-donating (Me and OMe) nor electronwithdrawing (F) groups affected the reaction, and corresponding tricyclic piperidines 8a−g were obtained in good chemical yields with excellent diastereo- and enantioselectivities (dr = >10:1, 92−96% ee’s for the major diastereomer). Naphthyltype substrate 8h was also suitable, and both enantio- and diastereoselectivities were likewise excellent (dr = >20:1, 95% ee for the major diastereomer). The relative and absolute stereochemistries of these products were surmised as depicted in Figures 1−3 by analogy to 8c, whose absolute stereo-
Figure 4. Chemical models for DFT calculations.
Based on our previous computational study,8 the detailed reaction pathway of the first [1,5]-hydride shift/cyclization process was investigated using simplified models. After exploring various conformations corresponding to the free rotation of three C−N bonds and the chair/boat-like sixmembered ring structures in the transition state (TS), we found the most energetically favorable reaction pathway affording the major product in a stereoselective manner (Figure 5). The [1,5]-hydride shift process via TS1, located at the highest energy level, was identified as the rate- and stereo-determining step, in good agreement with the results of D-labeling experiments (kD/kH = 2.5, Scheme S3 in the Supporting Information (SI)). The subsequent cyclization process was found to proceed smoothly through the lower-energy TS2 without any conformational change. Hydrogen bonds between the phosphoryl oxygen and the N-benzyl group controlled the relative orientation of electron-deficient olefin and amine moieties through the [1,5]-hydride shift/cyclization process. Although these structural features were also observed in other diastereomeric TSs leading to minor enantiomer and 6204
DOI: 10.1021/jacs.8b02761 J. Am. Chem. Soc. 2018, 140, 6203−6207
Communication
Journal of the American Chemical Society
tion by an achiral catalyst (second hydride shift). The key to achieving excellent enantioselectivity was the employment of a benzyl group having an electron-withdrawing moiety. Various substrates were applicable to this asymmetric reaction, and corresponding tricyclic piperidines were obtained in good chemical yields and with excellent diastereo- and enantioselectivities (dr = >10:1, 91−96% ee’s for the major diastereomer). DFT calculations revealed that the cooperative action of the hydrogen bond and the narrow chiral space contributes to stereoinduction in the stereo-determining first [1,5]-hydride shift process. Further investigations for the development of another chiral transformation by exploiting this type of sequential reaction are under way in our laboratory.
Figure 5. Gibbs free energy profile of the [1,5]-hydride shift/ cyclization process (in kcal/mol). Sum of submodel and PAmodel is set to zero.
■
diastereomers in the [1,5]-hydride shift process, TS1 was the most stable (Figure S3 and Table S2, SI). Focusing on the rate- and stereo-determining TS1, the origin of the high enantioselectivity was further addressed using realistic models (TSmajor and TSminor, affording major and minor enantiomers, respectively, Figure 6). TSmajor is 2.4 kcal/
ASSOCIATED CONTENT
S Supporting Information *
The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/jacs.8b02761. Experimental procedures, analytical data, DFT calculation, and Cartesian coordinates (PDF) 1 H, 13C, and 19F NMR and HPLC spectra of new compounds (PDF) X-ray crystallographic data for 8c (CIF) TSminor (XYZ) TSmajor (XYZ) TS1rs_B2_22_TS1 (XYZ) TS1rr_B2_33 (XYZ) TS1ss_B1_33 (XYZ) TS1sr_B1_33 (XYZ)
■
AUTHOR INFORMATION
Corresponding Authors
*
[email protected] *
[email protected] ORCID
Keiji Mori: 0000-0002-9878-993X Masahiro Yamanaka: 0000-0001-7978-620X Takahiko Akiyama: 0000-0003-4709-4107
Figure 6. 3D structures and relative energies of TSmajor and TSminor. Relative energies (kcal/mol) are in parentheses. Bond lengths are in Å.
mol more stable than TSminor, in good agreement with the experimentally observed stereochemical outcome. Introduction of considerably bulky 2,4,6-tricyclohexylphenyl groups (orange) provides a narrow chiral space to position the substrate at the center of the chiral space. The hydrogen bond between the phosphoryl oxygen and the N-benzyl group plays a key role in holding the amine moiety in a suitable position for the sequential [1,5]-hydride shift/cyclization process. Either one of the two N-benzyl groups (red or blue) coordinates with the phosphoryl oxygen, depending on the selective hydride shift of prochiral hydrogen atoms. The substrate fits better into the narrow chiral space in TSmajor than in TSminor. In the energetically less favorable TSminor, the magnesium bisphosphate catalyst and the malonate moiety were structurally distorted due to the considerably bulky 3,3′-substituents (Figure S4, SI). In summary, we have developed an asymmetric double C(sp3)−H bond functionalization triggered by a sequential hydride shift/cyclization process. This reaction consists of two stereoselective C(sp3)−H bond functionalizations: (1) a highly enantio- and diastereoselective C(sp3)−H bond functionalization by chiral magnesium bisphosphate (first hydride shift), and (2) a highly diastereoselective C(sp3)−H bond functionaliza-
Notes
The authors declare no competing financial interest.
■
ACKNOWLEDGMENTS We thank Dr. Koya Inomata and Prof. Kunio Mochida of Gakushuin University for X-ray analysis. This work was partially supported by Grants-in-Aid for Scientific Research (B) (26288053, 17KT0011, and 17H03060) from the Japan Society for the Promotion of Science, and grants from The Uehara Memorial Foundation, The Naito Foundation, and Inoue Foundation of Science.
■
REFERENCES
(1) For recent reviews on C−H activation, see: (a) Godula, K.; Sames, D. Science 2006, 312, 67. (b) Bergman, R. G. Nature 2007, 446, 391. (c) Alberico, D.; Scott, M. E.; Lautens, M. Chem. Rev. 2007, 107, 174. (d) Davies, H. M. L.; Manning, J. R. Nature 2008, 451, 417. (e) Chen, X.; Engle, K. M.; Wang, D.-H.; Yu, J.-Q. Angew. Chem., Int. Ed. 2009, 48, 5094. (f) Jazzar, R.; Hitce, J.; Renaudat, A.; SofackKreutzer, J.; Baudoin, O. Chem. - Eur. J. 2010, 16, 2654. (g) Lyons, T. W.; Sanford, M. S. Chem. Rev. 2010, 110, 1147. (h) Davies, H. M. L.; Du Bois, J.; Yu, J.-Q. Chem. Soc. Rev. 2011, 40, 1855. (i) Brückl, T.; Baxter, R. D.; Ishihara, Y.; Baran, P. S. Acc. Chem. Res. 2012, 45, 826. 6205
DOI: 10.1021/jacs.8b02761 J. Am. Chem. Soc. 2018, 140, 6203−6207
Communication
Journal of the American Chemical Society (j) Qin, Y.; Lv, J.; Luo, S. Tetrahedron Lett. 2014, 55, 551. (k) Davies, H. M. L.; Morton, D. J. Org. Chem. 2016, 81, 343. (2) For recent reviews on internal redox processes, see: (a) Tobisu, M.; Chatani, N. Angew. Chem., Int. Ed. 2006, 45, 1683. (b) Pan, S. C. Beilstein J. Org. Chem. 2012, 8, 1374. (c) Wang, M. ChemCatChem 2013, 5, 1291. (d) Peng, B.; Maulide, N. Chem. - Eur. J. 2013, 19, 13274. (e) Wang, L.; Xiao, J. Adv. Synth. Catal. 2014, 356, 1137. (f) Haibach, M. C.; Seidel, D. Angew. Chem., Int. Ed. 2014, 53, 5010. (g) Kwon, S. J.; Kim, D. Y. Chem. Rec. 2016, 16, 1191. (3) These types of reactions are classified under the term “tert-amino effect”. For reviews, see: (a) Meth-Cohn, O.; Suschitzky, H. Adv. Heterocycl. Chem. 1972, 14, 211. (b) Verboom, W.; Reinhoudt, D. N. Recl. Trav. Chim. Pays-Bas 1990, 109, 311. (c) Meth-Cohn, O. Adv. Heterocycl. Chem. 1996, 65, 1. (d) Quintela, J. M. Recent Res. Dev. Org. Chem. 2003, 7, 259. (e) Matyus, P.; Elias, O.; Tapolcsanyi, P.; Polonka-Balint, A.; Halasz-Dajka, B. Synthesis 2006, 2006, 2625. (4) For selected examples of internal redox reactions, see: (a) Pastine, S. J.; McQuaid, K. M.; Sames, D. J. Am. Chem. Soc. 2005, 127, 12180. (b) Pastine, S. J.; Sames, D. Org. Lett. 2005, 7, 5429. (c) PolonkaBálint, A.; Saraceno, C.; Ludányi, K.; Bényei, A.; Mátyus, P. Synlett 2008, 2008, 2846. (d) Zhang, C.; Murarka, S.; Seidel, D. J. Org. Chem. 2009, 74, 419. (e) McQuaid, K. M.; Sames, D. J. Am. Chem. Soc. 2009, 131, 402. (f) Shikanai, D.; Murase, H.; Hata, T.; Urabe, H. J. Am. Chem. Soc. 2009, 131, 3166. (g) Ruble, J. C.; Hurd, A. R.; Johnson, T. A.; Sherry, D. A.; Barbachyn, M.; Toogood, R. P. L.; Bundy, G. L.; Graber, D. R.; Kamilar, G. M. J. Am. Chem. Soc. 2009, 131, 3991. (h) Mahoney, M. J.; Moon, D. T.; Hollinger, J.; Fillion, E. Tetrahedron Lett. 2009, 50, 4706. (i) McQuaid, K. M.; Long, J. Z.; Sames, D. Org. Lett. 2009, 11, 2972. (j) Vadola, P. A.; Sames, D. J. Am. Chem. Soc. 2009, 131, 16525. (k) Zhou, G.; Zhang, J. Chem. Commun. 2010, 46, 6593. (l) Jurberg, I. D.; Peng, B.; Wöstefeld, E.; Wasserloos, M.; Maulide, N. Angew. Chem., Int. Ed. 2012, 51, 1950. (m) Sugiishi, T.; Nakamura, H. J. Am. Chem. Soc. 2012, 134, 2504. (n) Han, Y.-Y.; Han, W.-Y.; Zhang, X.-M.; Yuan, W.-C.; Hou, X. Org. Lett. 2012, 14, 4054. (o) Vadola, P. A.; Carrera, I.; Sames, D. J. Org. Chem. 2012, 77, 6689. (p) Gao, X.; Gaddam, V.; Altenhofer, E.; Tata, R. R.; Cai, Z.; Yongpruksa, N. A.; Garimallaprabhakaran, K.; Harmata, M. Angew. Chem., Int. Ed. 2012, 51, 7016. (q) Chen, D.-F.; Han, Z.-Y.; He, Y.-P.; Yu, J.; Gong, L.-Z. Angew. Chem., Int. Ed. 2012, 51, 12307. (r) Shaaban, S.; Maulide, N.; Peng, B. Synlett 2013, 24, 1722. (s) Cera, G.; Chiarucci, M.; Dosi, F.; Bandini, M. Adv. Synth. Catal. 2013, 355, 2227. (t) Dieckmann, A.; Richers, M. T.; Platonova, A. Y.; Zhang, C.; Seidel, D.; Houk, N. K. J. Org. Chem. 2013, 78, 4132. (u) Alajarin, M.; Bonillo, B.; Marin-Luna, M.; Sanchez-Andrada, P.; Vidal, A. Chem. - Eur. J. 2013, 19, 16093. (v) Vidal, A.; Marin-Luna, M.; Alajarin, M. Eur. J. Org. Chem. 2014, 2014, 878. (w) Chang, Y.-Z.; Li, M.-L.; Zhao, W.-F.; Wen, X.; Sun, H.; Xu, Q.-L. J. Org. Chem. 2015, 80, 9620. (x) Suh, C. W.; Kwon, S. J.; Kim, D. Y. Org. Lett. 2017, 19, 1334. (y) Li, S.-S.; Zhou, L.; Wang, L.; Zhao, H.; Yu, L.; Xiao, J. Org. Lett. 2018, 20, 138. (5) For other types of internal redox reactions, see: (a) Pahadi, N. K.; Paley, M.; Jana, R.; Waetzig, S. R.; Tunge, J. A. J. Am. Chem. Soc. 2009, 131, 16626. (b) Zhang, C.; Seidel, D. J. Am. Chem. Soc. 2010, 132, 1798. (c) Deb, I.; Seidel, D. Tetrahedron Lett. 2010, 51, 2945. (d) Zhang, C.; Das, D.; Seidel, D. Chem. Sci. 2011, 2, 233. (e) Mao, H.; Xu, R.; Wan, J.; Jiang; Sun, Z. C.; Pan, Y. Chem. - Eur. J. 2010, 16, 13352. (f) Deb, I.; Das, D.; Seidel, D. Org. Lett. 2011, 13, 812. (g) Mao, H.; Wang, S.; Yu, P.; Lv, H.; Xu, R.; Pan, Y. J. Org. Chem. 2011, 76, 1167. (h) Das, D.; Richers, M. T.; Ma, L.; Seidel, D. Org. Lett. 2011, 13, 6584. (i) Ma, L.; Chen, W.; Seidel, D. J. Am. Chem. Soc. 2012, 134, 15305. (j) Das, D.; Sun, A. X.; Seidel, D. Angew. Chem., Int. Ed. 2013, 52, 3765. (k) Das, D.; Seidel, D. Org. Lett. 2013, 15, 4358. (l) Zheng, Q.-H.; Meng, W.; Jiang, G.-J.; Yu, Z.-X. Org. Lett. 2013, 15, 5928. (m) Chen, W.; Kang, Y. K.; Wilde, R. G.; Seidel, D. 2014, 53, 5179. (n) Richers, M. T.; Breugst, M.; Platonova, A. Y.; Ullrich, A.; Dieckmann, A.; Houk, K. N.; Seidel, D. J. Am. Chem. Soc. 2014, 136, 6123. (o) Kang, Y.; Chen, W.; Breugst, M.; Seidel, D. J. Org. Chem. 2015, 80, 9628. (p) Ma, L.; Seidel, D. Chem. - Eur. J. 2015, 21, 12908. (6) For examples of enantioselective internal redox reactions, see: (a) Murarka, S.; Deb, I.; Zhang, C.; Seidel, D. J. Am. Chem. Soc. 2009,
131, 13226. (b) Kang, Y. K.; Kim, S. M.; Kim, D. Y. J. Am. Chem. Soc. 2010, 132, 11847. (c) Cao, W.; Liu, X.; Wang, W.; Lin, L.; Feng, X. Org. Lett. 2011, 13, 600. (d) Zhou, G.; Liu, F.; Zhang, J. Chem. - Eur. J. 2011, 17, 3101. (e) He, Y.-P.; Du, Y.-L.; Luo, S.-W.; Gong, L. Z. Tetrahedron Lett. 2011, 52, 7064. (f) Chen, L.; Zhang, L.; Lv, Z.; Cheng, J.-P.; Luo, S. Chem. - Eur. J. 2012, 18, 8891. (g) Zhang, L.; Chen, L.; Lv, Z.; Cheng, J.-P.; Luo, S. Chem. - Asian J. 2012, 7, 2569. (h) Jiao, Z.-W.; Zhang, S.-Y.; He, C.; Tu, Y.-Q.; Wang, S.-H.; Zhang, F.-M.; Zhang, Y.-Q.; Li, H. Angew. Chem., Int. Ed. 2012, 51, 8811. (i) Kang, Y. K.; Kim, D. Y. Adv. Synth. Catal. 2013, 355, 3131. (j) Suh, C. W.; Woo, S. B.; Kim, D. Y. Asian J. Org. Chem. 2014, 3, 399. (k) Kang, Y. K.; Kim, D. Y. Chem. Commun. 2014, 50, 222. (l) Suh, C. W.; Kim, D. Y. Org. Lett. 2014, 16, 5374. (m) Yu, J.; Li, N.; Chen, D.F.; Luo, S.-W. Tetrahedron Lett. 2014, 55, 2859. (n) Cao, W.; Liu, X.; Guo, J.; Lin, L.; Feng, X. Chem. - Eur. J. 2015, 21, 1632. See also ref 7i. (7) For the internal redox reaction developed by our group, see: (a) Mori, K.; Ohshima, Y.; Ehara, K.; Akiyama, T. Chem. Lett. 2009, 38, 524. (b) Mori, K.; Kawasaki, T.; Sueoka, S.; Akiyama, T. Org. Lett. 2010, 12, 1732. (c) Mori, K.; Sueoka, S.; Akiyama, T. J. Am. Chem. Soc. 2011, 133, 2424. (d) Mori, K.; Sueoka, S.; Akiyama, T. Chem. Lett. 2011, 40, 1386. (e) Mori, K.; Kawasaki, T.; Akiyama, T. Org. Lett. 2012, 14, 1436. (f) Mori, K.; Kurihara, K.; Akiyama, T. Chem. Commun. 2014, 50, 3729. (g) Mori, K.; Umehara, N.; Akiyama, T. Adv. Synth. Catal. 2015, 357, 901. (h) Yoshida, T.; Mori, K. Chem. Commun. 2017, 53, 4319. For an asymmetric version of internal redox reaction catalyzed by chiral phosphoric acid, see: (i) Mori, K.; Ehara, K.; Kurihara, K.; Akiyama, T. J. Am. Chem. Soc. 2011, 133, 6166. (8) Mori, K.; Kurihara, K.; Yabe, S.; Yamanaka, M.; Akiyama, T. J. Am. Chem. Soc. 2014, 136, 3744. (9) For pioneering works on chiral phosphoric acid catalysis, see: (a) Akiyama, T.; Itoh, J.; Yokota, K.; Fuchibe, K. Angew. Chem., Int. Ed. 2004, 43, 1566. (b) Uraguchi, D.; Terada, M. J. Am. Chem. Soc. 2004, 126, 5356. (10) For reviews on chiral phosphoric acid catalysis, see: (a) Akiyama, T.; Itoh, J.; Fuchibe, K. Adv. Synth. Catal. 2006, 348, 999. (b) Akiyama, T. Chem. Rev. 2007, 107, 5744. (c) Terada, M. Chem. Commun. 2008, 4097. (d) Terada, M. Synthesis 2010, 2010, 1929. (e) Zamfir, A.; Schenker, S.; Freund, M.; Tsogoeva, S. M. Org. Biomol. Chem. 2010, 8, 5262. (f) Terada, M. Curr. Org. Chem. 2011, 15, 2227. (g) Rueping, M.; Kuenkel, A.; Atodiresei, I. Chem. Soc. Rev. 2011, 40, 4539. (h) Parmar, D.; Sugiono, E.; Raja, S.; Rueping, M. Chem. Rev. 2014, 114, 9047. (i) Yang, Z.-P.; Zhang, W.; You, S.-L. J. Org. Chem. 2014, 79, 7785. (j) Parmar, D.; Sugiono, E.; Raja, S.; Rueping, M. Chem. Rev. 2017, 117, 10608. (k) Merad, J.; Lalli, C.; Bernadat, G.; Maury, J.; Masson, G. Chem. - Eur. J. 2018, 24, 3925. (11) For recent reviews combining metals and Brønsted acids, see: (a) Lacour, J.; Moraleda, D. Chem. Commun. 2009, 7073. (b) Shao, Z. H.; Zhang, H. B. Chem. Soc. Rev. 2009, 38, 2745. (c) Rueping, M.; Koenigs, R. M.; Atodiresei, I. Chem. - Eur. J. 2010, 16, 9350. (d) Hashmi, A. S. K.; Hubbert, C. Angew. Chem., Int. Ed. 2010, 49, 1010. (e) Phipps, R. J.; Hamilton, G. L.; Toste, F. D. Nat. Chem. 2012, 4, 603. (f) Parra, A.; Reboredo, S.; Martín Castro, A. M.; Aleman, J. Org. Biomol. Chem. 2012, 10, 5001. (g) Mahlau, M.; List, B. Angew. Chem., Int. Ed. 2013, 52, 518. (h) Brak, K.; Jacobsen, E. N. Angew. Chem., Int. Ed. 2013, 52, 534. (i) Chen, D.-F.; Han, Z.-Y.; Zhou, X.-L.; Gong, L.-Z. Acc. Chem. Res. 2014, 47, 2365. (12) For asymmetric reactions with chiral magnesium bisphosphate, see: (a) Ingle, G. K.; Liang, Y.; Mormino, M.; Li, G.; Fronczek, F. R.; Antilla, J. C. Org. Lett. 2011, 13, 2054. (b) Larson, S. E.; Li, G.; Rowland, G. B.; Junge, D.; Huang, R.; Woodcock, H. L.; Antilla, J. C. Org. Lett. 2011, 13, 2188. (c) Li, G.; Liang, T.; Wojtas, L.; Antilla, J. C. Angew. Chem., Int. Ed. 2013, 52, 4628. (d) Della Sala, G. Tetrahedron 2013, 69, 50. See also refs 6f,g. (13) Only two diastereomers were observed in this reaction, even though 5 has three stereogenic centers. (14) Judged by 1H NMR analysis, relative stereochemistries of the two diastereomers of 5 were determined to be cis and trans in the ring junction (JH‑H = 10.8 Hz in 5a, JH‑H = 3.2 Hz in 5b). These results 6206
DOI: 10.1021/jacs.8b02761 J. Am. Chem. Soc. 2018, 140, 6203−6207
Communication
Journal of the American Chemical Society further support our proposal, in which stereoselectivity was mostly determined at the first hydride shift/cyclization process.
(15) Computational details are shown in Supporting Information. (16) For selected examples of theoretical studies on chiral phosphoric acid catalysis, see: (a) Yamanaka, M.; Itoh, J.; Fuchibe, K.; Akiyama, T. J. Am. Chem. Soc. 2007, 129, 6756. (b) Simón, L.; Goodman, J. M. J. Am. Chem. Soc. 2008, 130, 8741. (c) Marcelli, T.; Hammar, P.; Himo, F. Chem. - Eur. J. 2008, 14, 8562. (d) Yamanaka, M.; Hirata, T. J. Org. Chem. 2009, 74, 3266. (e) Simón, L.; Goodman, J. M. J. Org. Chem. 2011, 76, 1775. (f) Mori, K.; Ichikawa, Y.; Kobayashi, M.; Shibata, Y.; Yamanaka, M.; Akiyama, T. J. Am. Chem. Soc. 2013, 135, 3964. (g) Reid, J. P.; Goodman, J. M. J. Am. Chem. Soc. 2016, 138, 7910. (h) Champagne, P. A.; Houk, K. N. J. Am. Chem. Soc. 2016, 138, 12356. (i) Li, F.; Korenaga, T.; Nakanishi, T.; Kikuchi, J.; Terada, M. J. Am. Chem. Soc. 2018, 140, 2629. See also refs 6f,g.
6207
DOI: 10.1021/jacs.8b02761 J. Am. Chem. Soc. 2018, 140, 6203−6207
