Subscribe to RSS
Please copy the URL and add it into your RSS Feed Reader.
https://www.thieme-connect.de/rss/thieme/en/10.1055-s-00000084.xml
Synthesis 2016; 48(12): 1825-1854
DOI: 10.1055/s-0035-1560437
DOI: 10.1055/s-0035-1560437
special topic
Cyclization of Imides to 2-Azabicycles via Aminoketyl Radicals by Using Samarium(II) Iodide–Water: Reaction Development, Synthetic Scope, and Mechanistic Studies
Further Information
Publication History
Received: 27 January 2016
Accepted after revision: 01 March 2016
Publication Date:
27 April 2016 (online)
◊ To whom correspondence about crystallographic data should be addressed
Dedicated to Professor Henri Kagan
Abstract
The first highly selective method for direct addition of aminoketyl radicals [R–C•(O–)NR1R2], generated from five- or six-membered cyclic imides, to nonactivated π-systems by using the SmI2–H2O reagent is reported. The transformation is operationally simple, scalable, and provides access to valuable angular 2-azabicycles containing three contiguous stereocenters with excellent diastereoselectivity (>95:5 dr). The protocol accommodates a wide range of π-acceptors that can be modulated by the alcohol additive used. Notably, the transformation provides the first general method for generation of aminoketyl radicals by a direct electron capture to amide bonds, thus opening new vistas for applications of these underutilized intermediates in a diverse array of open-shell reaction pathways. Systematic studies on the effects of additives, the scope and limitations of the reaction, and the reaction mechanism are reported.
Key words
azabicycles - samarium diiodide - reductive coupling - aminoketyl radicals - stereoselectivity - cyclizations - umpolungSupporting Information
- Supporting information for this article is available online at http://dx.doi.org/10.1055/s-0035-1560437.
- Supporting Information
-
References
- 1 Girard P, Namy JL, Kagan HB. J. Am. Chem. Soc. 1980; 102: 2693
- 2 Procter DJ, Flowers RA. II, Skrydstrup T. Organic Synthesis using Samarium Diiodide: A Practical Guide . RSC Publishing; Cambridge: 2010
- 3a Szostak M, Fazakerley NJ, Parmar D, Procter DJ. Chem. Rev. 2014; 114: 5959
- 3b Szostak M, Spain M, Procter DJ. Chem. Soc. Rev. 2013; 42: 9155
- 3c Beemelmanns C, Reissig H.-U. Chem. Soc. Rev. 2011; 40: 2199
- 3d Kagan HB. Tetrahedron 2003; 59: 10351
- 3e Krief A, Laval A.-M. Chem. Rev. 1999; 99: 745
- 3f Molander GA, Harris CR. Chem. Rev. 1996; 96: 307
- 3g Gopalaiah K, Kagan HB. Chem. Rec. 2013; 13: 187
- 3h Just-Baringo X, Procter DJ. Acc. Chem. Res. 2015; 48: 1263
- 3i Concellón JM, Rodríguez-Solla H, Concellón C, del Amo V. Chem. Soc. Rev. 2010; 39: 4103
- 3j Concellón JM, Rodríguez-Solla H. Eur. J. Org. Chem. 2006; 1613
- 3k Concellón JM, Rodríguez-Solla H. Chem. Soc. Rev. 2004; 33: 599
- 3l Berndt M, Gross S, Hölemann A, Reissig H.-U. Synlett 2004; 422
- 3m Beemelmanns C, Reissig H.-U. Pure Appl. Chem. 2011; 83: 507
- 3n Ebran JP, Jensen CM, Johannesen SA, Karaffa J, Lindsay KB, Taaning R, Skrydstrup T. Org. Biomol. Chem. 2006; 4: 3553
- 4a Afagh NA, Yudin AK. Angew. Chem. Int. Ed. 2010; 49: 262
- 4b Mahatthananchai J, Dumas A, Bode JW. Angew. Chem. Int. Ed. 2012; 51: 10954
- 4c For a review on chemoselective SmI2 reactions, see ref. 3b.
- 5a Comprehensive Organic Synthesis . Trost BM, Fleming I. Pergamon; Oxford: 1991
- 5b Gansäuer A, Bluhm H. Chem. Rev. 2000; 100: 2771
- 5c Szostak M, Procter DJ. Angew. Chem. Int. Ed. 2012; 51: 9238
- 5d Streuff J. Synthesis 2013; 45: 281
- 5e Radicals in Synthesis I. Gansäuer A. Springer; Berlin: 2006
- 5f Radicals in Synthesis II. Gansäuer A. Springer; Berlin: 2006
- 6a Szostak M, Spain M, Parmar D, Procter DJ. Chem. Commun. 2012; 48: 330
- 6b Dahlén A, Hilmersson G. Eur. J. Inorg. Chem. 2004; 3393
- 6c Kagan HB, Namy JL In Lanthanides: Chemistry and Use in Organic Synthesis . Kobayashi S., Springer; New York: 1999: 155
- 7 Szostak M, Spain M, Procter DJ. J. Am. Chem. Soc. 2014; 136: 8459
- 8 Tsuruta H, Imamoto T, Yamaguchi K. Chem. Commun. 1999; 1703
- 9a Rudkin IM, Miller LC, Procter DJ. Organomet. Chem. 2008; 34: 19
- 9b Helm MD, Da Silva M, Sucunza D, Findley TJ. K, Procter DJ. Angew. Chem. Int. Ed. 2009; 48: 9315
- 9c Fazakerley NJ, Helm MD, Procter DJ. Chem. Eur. J. 2013; 19: 6718
- 9d Cha JY, Yeoman JT. S, Reisman SE. J. Am. Chem. Soc. 2011; 133: 14964
- 9e Li Z, Nakashige M, Chain WJ. J. Am. Chem. Soc. 2011; 133: 6553
- 10a Jensen CM, Lindsay KB, Taaning RH, Karaffa J, Hansen AM, Skrydstrup T. J. Am. Chem. Soc. 2005; 127: 6544
- 10b Hansen AM, Lindsay KB, Antharjanam PK. S, Karaffa J, Daasbjerg K, Flowers RA. II, Skrydstrup T. J. Am. Chem. Soc. 2006; 128: 9616
- 10c Taaning RH, Lindsay KB, Schiøtt B, Daasbjerg K, Skrydstrup T. J. Am. Chem. Soc. 2009; 131: 10253
- 10d Masson G, Cividino P, Py S, Vallée Y. Angew. Chem. Int. Ed. 2003; 42: 2265
- 10e Cividino P, Py S, Delair P, Greene AE. J. Org. Chem. 2007; 72: 485
- 10f Burchak ON, Philouze C, Chavant PY, Py S. Org. Lett. 2008; 10: 3021
- 10g Desvergnes S, Py S, Vallée Y. J. Org. Chem. 2005; 70: 1459
- 10h Masson G, Philouze C, Py S. Org. Biomol. Chem. 2005; 3: 2067
- 10i Gilles P, Py S. Org. Lett. 2012; 14: 1042
- 10j Peltier HM, McMahon JP, Patterson AW, Ellman JA. J. Am. Chem. Soc. 2006; 128: 16018
- 10k Mai CK, Sammons MF, Sammakia T. Angew. Chem. Int. Ed. 2010; 49: 2397
- 10l Phillips EM, Roberts JM, Scheidt K. Org. Lett. 2010; 12: 2830
- 10m Wenderski TA, Huang S, Pettus TR. R. J. Org. Chem. 2009; 74: 4104
- 10n Rao CN, Lentz D, Reissig HU. Angew. Chem. Int. Ed. 2015; 54: 2750
- 11a Dahlén A, Hilmersson G. Tetrahedron Lett. 2002; 43: 7197
- 11b Dahlén A, Hilmersson G. Chem. Eur. J. 2003; 9: 1123
- 11c Dahlén A, Hilmersson G. J. Am. Chem. Soc. 2005; 127: 8340
- 11d Dahlén A, Nilsson Å, Hilmersson G. J. Org. Chem. 2006; 71: 1576
- 11e Ankner T, Hilmersson G. Tetrahedron 2009; 65: 10856
- 11f Ankner T, Hilmersson G. Org. Lett. 2009; 11: 503
- 11g Ankner T, Stålsmeden AS, Hilmersson G. Chem. Commun. 2013; 49: 6867
- 11h Szostak M, Spain M, Procter DJ. Chem. Commun. 2011; 47: 10254
- 11i Szostak M, Spain M, Procter DJ. Org. Lett. 2012; 14: 840
- 11j Maity S, Hoz S. Chem. Eur. J. 2015; 21: 18394
- 12a Beemelmanns C, Reissig H.-U. Angew. Chem. Int. Ed. 2010; 49: 8021
- 12b Beemelmanns C, Gross S, Reissig H.-U. Chem. Eur. J. 2013; 19: 17801
- 12c Saadi J, Lentz D, Reissig H.-U. Org. Lett. 2009; 11: 3334
- 12d Wefelscheid UK, Berndt M, Reissig H.-U. Eur. J. Org. Chem. 2008; 3635
- 12e Aulenta F, Berndt M, Brüdgam I, Hartl H, Sörgel S, Reissig H.-U. Chem. Eur. J. 2007; 13: 6047
- 12f Beemelmanns C, Reissig H.-U. Org. Biomol. Chem. 2009; 7: 4475
- 12g Beemelmanns C, Lentz D, Reissig H.-U. Chem. Eur. J. 2011; 17: 9720
- 12h Halder S, Hoz S. J. Org. Chem. 2014; 79: 2682
- 12i Rao CN, Hoz S. J. Org. Chem. 2012; 77: 9199
- 13a Miller RS, Sealy JM, Shabangi M, Kuhlman ML, Fuchs JR, Flowers RA. II. J. Am. Chem. Soc. 2000; 122: 7718
- 13b Prasad E, Flowers RA. II. J. Am. Chem. Soc. 2002; 124: 6895
- 13c Teprovich JA. Jr, Balili MN, Pintauer T, Flowers RA. II. Angew. Chem. Int. Ed. 2007; 46: 8160
- 13d Sadasivam DV, Antharjanam PK. S, Prasad E, Flowers RA. II. J. Am. Chem. Soc. 2008; 130: 7228
- 13e Choquette KA, Sadasivam DV, Flowers RA. II. J. Am. Chem. Soc. 2010; 132: 17396
- 13f Choquette KA, Sadasivam DV, Flowers RA. II. J. Am. Chem. Soc. 2011; 133: 10655
- 13g McDonald CE, Ramsey JD, Sampsell DG, Butler JA, Cecchini MR. Org. Lett. 2010; 12: 5178
- 13h Berndt M, Hölemann A, Niermann A, Bentz C, Zimmer R, Reissig HU. Eur. J. Org. Chem. 2012; 1299
- 13i Curran DP, Gu X, Zhang W, Dowd P. Tetrahedron 1997; 53: 9023
- 13j Rao CN, Hoz S. J. Am. Chem. Soc. 2011; 133: 14795
- 13k Chciuk TV, Hilmersson G, Flowers RA. II. J. Org. Chem. 2014; 79: 9441
- 13l Chciuk TV, Flowers RA. II. J. Am. Chem. Soc. 2015; 137: 11526
- 13m Yitzhaki O, Hoz S. Chem. Eur. J. 2015; 21: 9242
- 14a Duffy LA, Matsubara H, Procter DJ. J. Am. Chem. Soc. 2008; 130: 1136
- 14b Parmar D, Duffy LA, Sadasivam DV, Matsubara H, Bradley PA, Flowers RA. II, Procter DJ. J. Am. Chem. Soc. 2009; 131: 15467
- 14c Parmar D, Price K, Spain M, Matsubara H, Bradley PA, Procter DJ. J. Am. Chem. Soc. 2011; 133: 2418
- 14d Parmar D, Matsubara H, Price K, Spain M, Procter DJ. J. Am. Chem. Soc. 2012; 134: 12751
- 14e Guazzelli G, De Grazia S, Collins KD, Matsubara H, Spain M, Procter DJ. J. Am. Chem. Soc. 2009; 131: 7214
- 14f Collins KD, Oliveira JM, Guazzelli G, Sautier B, De Grazia S, Matsubara H, Helliwell M, Procter DJ. Chem. Eur. J. 2010; 16: 10240
- 14g Sautier B, Lyons SE, Webb MR, Procter DJ. Org. Lett. 2012; 14: 146
- 14h Sautier B, Collins KD, Procter DJ. Beilstein J. Org. Chem. 2013; 9: 1443
- 14i Yalavac I, Llyons SE, Webb MR, Procter DJ. Chem. Commun. 2014; 50: 12863
- 14j Harb HY, Procter DJ. Synlett 2012; 23: 6
- 14k Sautier B, Procter DJ. Chimia 2012; 66: 399
- 15a Flowers RA. II, Prasad E In Handbook on the Physics and Chemistry of Rare Earths . Vol. 36. Gschneidner KA. Jr, Bünzli JC, Pecharsky VK. Elsevier; Amsterdam: 2006: 393
- 15b Montalti M, Credi A, Prodi L, Gandolfi MT. Handbook of Photochemistry . 3rd ed. CRC Press; Boca Raton: 2006
- 16 Laurence C, Gal JF. Lewis Basicity and Affinity Scales: Data and Measurement . Wiley-Blackwell; Oxford: 2009
- 17 Shi S, Szostak M. Org. Lett. 2015; 17: 5144
- 18a Szostak M, Aubé J. Chem. Rev. 2013; 113: 5701
- 18b Szostak R, Aubé J, Szostak M. Chem. Commun. 2015; 51: 6395
- 18c Szostak R, Aubé J, Szostak M. J. Org. Chem. 2015; 80: 7905
- 18d Szostak M, Aubé J. Org. Biomol. Chem. 2011; 9: 27
- 19a Meng G, Szostak M. Org. Lett. 2015; 17: 4364
- 19b Meng G, Szostak M. Angew. Chem. Int. Ed. 2015; 54: 14518
- 19c Hu F, Patel M, Luo F, Flach C, Mendelsohn R, Garfunkel E, He H, Szostak M. J. Am. Chem. Soc. 2015; 137: 14473
- 19d Meng G, Szostak M. Org. Lett. 2016; 18: 796
- 19e Hu F, Lalanette R, Szostak M. Angew. Chem. Int. Ed. 2016; 55: 5062
- 19f Meng G, Szostak M. Org. Biomol. Chem. 2016; 14: DOI: 10.1039/c6ob00084c
- 20a Szostak M, Spain M, Eberhart AJ, Procter DJ. J. Am. Chem. Soc. 2014; 136: 2268
- 20b Szostak M, Spain M, Eberhart AJ, Procter DJ. J. Org. Chem. 2014; 79: 11988
- 20c Szostak M, Sautier B, Procter DJ. Chem. Commun. 2014; 50: 2518
- 20d Szostak M, Spain M, Procter DJ. Angew. Chem. Int. Ed. 2013; 52: 7237
- 20e Szostak M, Sautier B, Spain M, Behlendorf M, Procter DJ. Angew. Chem. Int. Ed. 2013; 52: 12559
- 20f Szostak M, Spain M, Procter DJ. Org. Lett. 2014; 16: 5052
- 20g Szostak M, Sautier B, Spain M, Procter DJ. Org. Lett. 2014; 16: 1092
- 21a von Sonntag C. Adv. Quantum Chem. 2007; 52: 5
- 21b Tureček F. Adv. Quantum Chem. 2007; 52: 89
- 21c Tureček F, Julian RR. Chem. Rev. 2013; 113: 6691
- 21d Tureček F. Mass Spectrom. 2013; 2: 3
- 21e Zhurov KO, Fornelli L, Wodrich MD, Laskay ÜA, Tsybin YO. Chem. Soc. Rev. 2013; 42: 5014
- 21f Syrstad EA, Tureček F. J. Am. Soc. Mass Spectrom. 2005; 16: 208
- 22a Ney JE, Wolfe JP. J. Am. Chem. Soc. 2005; 127: 8644
- 22b Maity S, Zhu M, Shinabery RS, Zheng N. Angew. Chem. Int. Ed. 2012; 51: 222
- 22c Basch CH, Brinck JA, Ramos JE, Habay SA, Yap GP. A. J. Org. Chem. 2012; 77: 10416
- 22d Shaw MH, Melikhova EY, Kloer DP, Whittingham WG, Bower JF. J. Am. Chem. Soc. 2013; 135: 4992
- 22e Belanger G, April M, Dauphin É, Roy S. J. Org. Chem. 2007; 72: 1104
- 22f Nicolai S, Waser J. Org. Lett. 2011; 13: 6324
- 22g Kwak YS, Winkler JD. J. Am. Chem. Soc. 2001; 123: 7429
- 22h Rahm A, Wulff WD. J. Am. Chem. Soc. 1996; 118: 1807
- 22i Yu J.-D, Ding W, Lian G.-Y, Song K.-S, Zhang D.-W, Gao X, Yang D. J. Org. Chem. 2010; 75: 3232
- 23 The Amide Linkage: Structural Significance in Chemistry, Biochemistry and Materials Science. Greenberg A, Breneman CM, Liebman JF. Wiley Interscience; New York: 2000
- 24a Szostak M, Spain M, Procter DJ. J. Org. Chem. 2014; 79: 2522
- 24b Enemærke RJ, Hertz T, Skrydstrup T, Daasbjerg K. Chem. Eur. J. 2000; 6: 3747
- 24c Enemærke RJ, Daasbjerg K, Skrydstrup T. Chem. Commun. 1999; 343
- 25 Austad BC, Calkins TL, Chase CE, Fang FG, Horstmann TE, Hu Y, Lewis BM, Niu X, Noland TA, Orr JD, Schnaderbeck MJ, Zhang H, Asakawa N, Asai N, Chiba H, Hasebe T, Hoshino Y, Ishizuka H, Kajima T, Kayano A, Komatsu Y, Kubota M, Kuroda H, Miyazawa M, Tagami K, Watanabe T. Synlett 2013; 24: 333 ; See also ref. 3b
- 26a Edmonds DJ, Johnston D, Procter DJ. Chem. Rev. 2004; 104: 3371
- 26b Nicolaou KC, Ellery SP, Chen JS. Angew. Chem. Int. Ed. 2009; 48: 7140
- 27a Radicals in Organic Synthesis . Renaud P, Sibi M. Wiley-VCH; Weinheim: 2001
- 27b Encyclopedia of Radicals in Chemistry, Biology and Materials. Chatgilialoglu C, Studer A. Wiley, Chichester; 2012:
- 27c Curran DP, Porter NA, Giese B. Stereochemistry of Radical Reactions: Concepts, Guidelines, and Synthetic Applications. VCH; Weinheim: 1996
- 28a Zubarev RA, Kelleher NL, McLafferty FW. J. Am. Chem. Soc. 1998; 120: 3265
- 28b Tureček F. J. Am. Chem. Soc. 2003; 125: 5954
- 28c Sawicka A, Skurski P, Hudgins RR, Simons J. J. Phys. Chem. B 2003; 107: 13505
- 28d Tureček F, Chen X, Hao C. J. Am. Chem. Soc. 2008; 130: 8818
- 28e Skurski P, Sobczyk M, Jakowski J, Simons J. Int. J. Mass Spectrom. 2007; 265: 197
- 28f Tureček F, Chung TW, Moss CL, Wyer JA, Ehlerding A, Holm AI. S, Zettergren H, Nielsen SB, Hvelplund P, Chamot-Rooke J, Bythell B, Paizs B. J. Am. Chem. Soc. 2010; 132: 10728
- 28g Moore BN, Ly T, Julian RR. J. Am. Chem. Soc. 2011; 133: 6997
- 28h Chung TW, Tureček F. Int. J. Mass Spectrom. 2011; 301: 55
- 29a Wu YD, Houk KN. J. Am. Chem. Soc. 1992; 114: 1656
- 29b Kefalidis CE, Perrin L, Maron L. Eur. J. Inorg. Chem. 2013; 4042
- 30a Shaffer SA, Tureček F, Cerny RL. J. Am. Chem. Soc. 1993; 115: 12117
- 30b Armstrong DA, Rauk A, Yu D. J. Am. Chem. Soc. 1993; 115: 666
- 30c Wayner DD. M, Clark KB, Rauk A, Yu D, Armstrong DA. A. J. Am. Chem. Soc. 1997; 119: 8925
- 31a Renaud P, Giraud L. Synthesis 1996; 913
- 31b Aurrecoechea JM, Suero R. ARKIVOC 2004; (xiv): 10
- 31c Hoffmann N, Bertrand S, Marinković S, Pesch J. Pure Appl. Chem. 2006; 78: 2227
- 32a Vacas T, Álvarez E, Chiara JL. Org. Lett. 2007; 9: 5445
- 32b Chiara JL, García Á, Cristóbal-Lumbroso G. J. Org. Chem. 2005; 70: 4142
- 32c Kanaoka Y. Acc. Chem. Res. 1978; 11: 407
- 32d Yoon UC, Mariano PS. Acc. Chem. Res. 2001; 34: 523
- 32e Griesbeck AG, Kramer W, Bartoschek A, Schmickler H. Org. Lett. 2001; 3: 537
- 32f Orzeszko A, Maurin JK, Niedźwiecka-Kornaś A, Kazimierczuk Z. Tetrahedron 1998; 54: 7517
- 32g Skrydstrup reported coupling of N-acyloxazolidinones through an addition mechanism: see refs. 10a–c.
- 32h Farcas S, Namy JL. Tetrahedron Lett. 2000; 41: 7299
- 32i Ha D.-C, Yun C.-S, Lee Y. J. Org. Chem. 2000; 65: 621
- 32j Farcas S, Namy J.-L. Tetrahedron Lett. 2001; 42: 879
- 33 Hartmann KH, Troll T. Tetrahedron 1995; 51: 4655
- 34a Lee CM, Kumler WD. J. Am. Chem. Soc. 1961; 83: 4586
- 34b Xu Q, Cheng B, Ye X, Zhai H. Org. Lett. 2009; 11: 4136
- 35a Malatesta V, Ingold KU. J. Am. Chem. Soc. 1981; 103: 609
- 35b Giese B. Angew. Chem. Int. Ed. Engl. 1989; 28: 969
- 35c Cohen T, Bhupathy M. Acc. Chem. Res. 1989; 22: 152
- 35d Buckmelter AJ, Kim AI, Rychnovsky SD. J. Am. Chem. Soc. 2000; 122: 9386
- 36a Szostak M, Spain M, Choquette KA, Flowers RA. II, Procter DA. J. Am. Chem. Soc. 2013; 135: 15702
- 36b Hoveyda AH, Evans DA, Fu GC. Chem. Rev. 1993; 93: 1307
- 37a Siengalewicz P, Mulzer J, Rinner U. Alkaloids Chem. Biol. 2013; 72: 1
- 37b Pilli RA, Rosso GB, de Oliveira MdaC. F. Nat. Prod. Rep. 2010; 27: 1908
- 37c Weinreb SM. Chem. Rev. 2006; 106: 2531
- 37d Sun S, McKenna CE. Expert Opin. Ther. Pat. 2011; 21: 1433
- 37e Grygorenko OO. Tetrahedron 2015; 71: 5169
- 37f Chen C, Kozikowski AP, Wood PL, Reynolds IJ, Ball RG, Pang YP. J. Med. Chem. 1992; 35: 1634
- 37g Teetz V, Geiger R, Gaul H. Tetrahedron Lett. 1984; 25: 4479
- 37h Reimann E, Ettmayr C, Polborn K. Monatsh. Chem. 2004; 135: 557
- 37i Lobo G, Monasterios M, Rodrigues J, Gamboa N, Capparelli MV, Martínez-Cuevas J, Lein M, Jung K, Abramjuk C, Charris J. Eur. J. Med. Chem. 2015; 96: 281
- 37j Crooks PA, Dwoskin LP, Ayers J, Grinevich V, Sumithran S. US 20050261334, 2005
- 37k Ji X, Xia C, Wang J, Su M, Zhang L, Dong T, Li Z, Wan X, Li J, Li J, Zhao L, Gao Z, Jiang H, Liu H. Eur. J. Med. Chem. 2014; 86: 242
- 37l Cohen F, Alicke B, Elliott LO, Flygare JA, Goncharov T, Keteltas SF, Franklin MC, Frankovitz S, Stephan J.-P, Tsui V, Vucic D, Wong H, Fairbrother WJ. J. Med. Chem. 2009; 52: 1723
- 37m Wilken J, Kossenjans M, Gröger H, Martens J. Tetrahedron: Asymmetry 1997; 8: 2007
- 37n Wilken J, Wallbaum S, Saak W, Haase D, Pohl S, Patkar LN, Dixit AN, Chittari P, Rajappa S, Martens J. Liebigs Ann. 1996; 927
- 37o Kawabata T, Nagato M, Takasu K, Fuji K. J. Am. Chem. Soc. 1997; 119: 3169
- 37p Kawabata T, Stragies R, Fukaya T, Fuji K. Chirality 2003; 15: 71
- 38 Pseudoanomeric stabilization of the aminoketyl radical in a five-membered ring system is less efficient due to geometrical constraints; see: Eliel EL, Wilen SH. Stereochemistry of Organic Compounds . Wiley-Blackwell; Oxford: 1994
- 39a Yacovan A, Hoz S, Bilkis I. J. Am. Chem. Soc. 1996; 118: 261
- 39b Tarnopolsky A, Hoz S. J. Am. Chem. Soc. 2007; 129: 3402
- 39c Amiel-Levy M, Hoz S. J. Am. Chem. Soc. 2009; 131: 8280
- 39d Upadhyay SK, Hoz S. J. Org. Chem. 2011; 76: 1355
- 39e Flowers RA. II. Synlett 2008; 1427
- 39f Chopade PR, Prasad E, Flowers RA. II. J. Am. Chem. Soc. 2004; 126: 44
- 39g Prasad E, Flowers RA. II. J. Am. Chem. Soc. 2005; 127: 18093
- 39h Sadasivam DV, Teprovich JA. Jr, Procter DJ, Flowers RA. II. Org. Lett. 2010; 12: 4140
- 39i See also ref. 13.
- 40 Reduction of nonactivated amides with Sm(II) reagents has been reported; see refs. 20a and 20b.
- 41a Hutton TK, Muir K, Procter DJ. Org. Lett. 2002; 4: 2345
- 41b Hutton TK, Muir KW, Procter DJ. Org. Lett. 2003; 5: 4811
- 42 Fessenden RW, Schuler RH. J. Chem. Phys. 1963; 39: 2147
- 43a Beckwith AL. J, Schiesser CH. Tetrahedron 1985; 41: 3925
- 43b Spellmeyer DC, Houk KN. J. Org. Chem. 1987; 52: 959
- 43c Beckwith AL. J. Tetrahedron 1981; 37: 3073
- 43d Giese B. Angew. Chem. Int. Ed. 1983; 22: 753
- 44 Molander GA, McKie JA. J. Org. Chem. 1995; 60: 872
- 45 Prasad E, Flowers RA. II. J. Am. Chem. Soc. 2002; 124: 6357
- 46 Williams DB. G, Blann K, Caddy J. Org. Prep. Proced. Int. 2001; 33: 565
- 47a Renaud P, Gerster M. Angew. Chem. Int. Ed. 1998; 37: 2562
- 47b Sibi MP, Porter NA. Acc. Chem. Res. 1999; 32: 163
- 47c Srikanth GS. C, Castle SL. Tetrahedron 2005; 61: 10377
- 48 Simmons EM, Hartwig JF. Angew. Chem. Int. Ed. 2012; 51: 3066
- 49 Espenson JH. Chemical Kinetics and Reaction Mechanisms . McGraw-Hill; New York: 2002
- 51a Newcomb M. Tetrahedron 1993; 49: 1151
- 51b Hasegawa E, Curran DP. Tetrahedron Lett. 1993; 34: 1717
- 51c Curran DP, Fevig TL, Jasperse CP, Totleben J. Synlett 1992; 943
- 52a Stevenson JP, Jackson WF, Tanko JM. J. Am. Chem. Soc. 2002; 124: 4271
- 52b Tanko JM, Gillmore JG, Friedline R, Chahma M. J. Org. Chem. 2005; 70: 4170
- 52c Tanko JM, Li X, Chahma M, Jackson WF, Spencer JN. J. Am. Chem. Soc. 2007; 129: 4181
- 53a Adler M, Adler S, Boche G. J. Phys. Org. Chem. 2005; 18: 193
- 53b Deslongchamps P. Stereoelectronic Effects in Organic Chemistry. Pergamon; Oxford: 1983
- 54 Kirby AJ, Komarov IV, Feeder N. J. Am. Chem. Soc. 1998; 120: 7101
- 55 Seebach D. Angew. Chem. Int. Ed. 2011; 50: 96
- 56a Maryanoff BE, Zhang HC, Cohen JH, Turchi IJ, Maryanoff CA. Chem. Rev. 2004; 104: 1431
- 56b See also refs. 20c and 20e.
- 57 Crystallographic data for compounds 8 and 54 have been deposited with the accession numbers CCDC 1449857 and 1449896, respectively, and can be obtained free of charge from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; Fax: +44(1223)336033; E-mail: deposit@ccdc.cam.ac.uk; Web site: www.ccdc.cam.ac.uk/conts/retrieving.html.
- 58 Roughley SD, Jordan A. J. Med. Chem. 2011; 54: 3451
For recent reviews on SmI2, see:
For reviews on chemoselective organic reactions, see:
For reviews on metal-mediated radical reactions, see:
For recent impressive applications, see:
For selected recent references on SmI2/H2O, see:
For selected recent references on SmI2/amine/H2O, see:
For selected recent references on SmI2/HMPA, see:
For selected recent mechanistic studies on SmI2 reductants, see:
The use of imides as radical precursors for cyclizations has been accomplished in specific cases; however, no general, synthetically useful, method has been developed, see:
For coupling of imides by a fragmentation mechanism, see:
For addition of organosamariums to imides, see: