Hydrogen Bonds as an Alternative Activation

New Strategies in Chemical Synthesis and Catalysis

Volumn , Issue , 2012, Pages 175-199

  Marqués López, Eugenia ^a   Herrera, Raquel P ^a,b  

^a UNIVERSITY OF ZARAGOZA   (Spain)

^b FUNDACIÓN ARAID   (Spain)

Author keywords

Aza henry Reaction; Friedel crafts alkylation Reaction; Hydrogen bond interactions; Michael addition; Organocatalysis; Thiourea

Indexed keywords

EID: 84884607357     PISSN: None     EISSN: None     Source Type: Book    
DOI: 10.1002/9783527645824.ch8     Document Type: Chapter

References (120)

1. Pellissier, H. (ed.) (2010) Recent Developments in Asymmetric Organocatalysis, RSC Publishing, Cambridge;
2. Berkessel, A. and Groger, H. (2005) Asymmetric Organocatalysis, Wiley-VCH Verlag GmbH, Weinheim;
3. Dalko, P.I. (ed.) (2007) Enantioselective Organocatalysis, Wiley-VCH Verlag GmbH, Weinheim;
4. List, B. (ed.) (2010) Asymmetric Organocatalysis, Topics in Current Chemistry, Vol. 291, Springer, Heidelberg.
5. de Figueiredo, R.M. and Christmann, M. (2007) Organocatalytic synthesis of drugs and bioactive natural products. Eur. J. Org. Chem., 2575-2600;
6. Marqués-López, E., Herrera, R.P., and Christmann, M. (2010) Asymmetric organocatalysis in total synthesis - a trial by fire. Nat. Prod. Rep., 27, 1138-1167.
7. Dalko, P.I. and Mosan, L. (2004) In the golden age of organocatalysis. Angew. Chem. Int. Ed., 43, 5138-5175.
8. Pihko, P.M., Majander, I., and Erkkilä, A. (2010) Enamine catalysis. Top. Curr. Chem., 291, 29-75;
9. Brazier, J.B. and Tomkinson, N.C.O. (2010) Secondary and primary amine catalysts for iminium catalysis. Top. Curr. Chem., 291, 281-347.
10. Berkessel, A. (2008) Organocatalysis by hydrogen bonding networks, in Organocatalysis, vol. 2 (eds M.T. Reetz, B. List, H. Jaroch, and H. Weinmann), Springer-Verlag, Berlin, Heidelberg, pp. 281-297;
11. Pihko, P.M. (ed.) (2009) Hydrogen Bonding in Organic Synthesis, Wiley-VCH Verlag GmbH, Weinheim;
12. Kerstin, E.-E. and Berkessel, A. (2010) Noncovalent organocatalysis based on hydrogen bonding: elucidation of reaction paths by computational methods. Top. Curr. Chem., 291, 1-27.
13. Ooi, T. and Maruoka, K. (2007) Recent advances in asymmetric phase-transfer catalysis. Angew. Chem. Int. Ed., 46, 4222-4266;
14. Hashimoto, T. and Maruoka, K. (2007) Recent development and application of chiral phase-transfer catalysts. Chem. Rev., 107, 5656-5682;
15. Maruoka, K. (ed.) (2008) Asymmetric Phase Transfer Catalysis, Wiley-VCH Verlag GmbH, Weinheim.
16. Engeldinger, E., Armspach, D., and Matt, D. (2003) Capped cyclodextrins. Chem. Rev., 103, 4147-4174.
17. Schreiner, P.R. (2003) Metal-free organocatalysis through explicit hydrogen bonding interactions. Chem. Soc. Rev., 32, 289-296;
18. Takemoto, Y. (2005) Recognition and activation by References 195 ureas and thioureas: stereoselective reactions using ureas and thioureas as hydrogen-bonding donors. Org. Biomol. Chem., 3, 4299-4306;
19. Connon, S.J. (2006) Organocatalysis mediated by (thio)urea derivatives. Chem. Eur. J., 12, 5418-5427;
20. Taylor, M.S. and Jacobsen, E.N. (2006) Asymmetric catalysis by chiral hydrogen-bond donors. Angew. Chem. Int. Ed., 45, 1520-1543;
21. Doyle, A.G. and Jacobsen, E.N. (2007) Small-molecules H-bond donors in asymmetric catalysis. Chem. Rev., 107, 5713-5743;
22. Miyabe, H. and Takemoto, Y. (2008) Discovery and Application of asymmetric reaction by multi-functional thioureas. Bull. Chem. Soc. Jpn., 81, 785-795;
23. Zhang, Z. and Schreiner, P.R. (2009) (Thio)urea organocatalysis - What can be learnt from anion recognition? Chem. Soc. Rev., 38, 1187-1198;
24. Marqués-López, E. and Herrera, R.P. (2009) El renacer de un Nuevo campo: la organocatálisis asimetrica. Tioureas como organocatalizadores. An. Quím., 105, 5-12.
25. Ishikawa, T. and Kumamoto, T. (2006) Guanidines in organic synthesis. Synthesis, 737-752;
26. Leow, D. and Tan, C.-H. (2010) Catalytic reactions of chiral guanidines and guanidinium salts. Synlett, 1589-1605.
27. Huang, Y., Unni, A.K., Thadani, A.N., and Rawal, V.H. (2003) Single enantiomers from a chiral-alcohol catalyst. Nature, 424, 146-146;
28. Thadani, A.N., Stankovic, A.R., and Rawal, V.H. (2004) Enantioselective Diels-Alder reactions catalyzed by hydrogen bonding. Proc. Natl. Acad. Sci. U.S.A., 101, 5846-5850.
29. McDougal, N.T. and Schaus, S.E. (2003) Asymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Brønsted acids. J. Am. Chem. Soc., 125, 12094-12095;
30. McDougal, N.T., Trevellini, W.L., Rodgen, S.A., Kliman, L.T., and Schaus, S.E. (2004) The development of the asymmetric Morita-Baylis-Hillman reaction catalyzed by chiral Brønsted acids. Adv. Synth. Catal., 346, 1231-1240;
31. Takizawa, S., Horii, A., and Sasai, H. (2010) Acid-base organocatalysts for the aza-Morita-Baylis-Hilmann reaction of nitroalkenes. Tetrahedron: Asymmetry, 21, 891-894.
32. Nugent, B.M., Yoder, R.A., and Johnston, J.N. (2004) Chiral proton catalysis: a catalytic enantioselective direct aza-Henry reaction. J. Am. Chem. Soc., 126, 3418-3419;
33. Hess, A.S., Yoder, R.A., and Johnston, J.N. (2006) Chiral proton catalysis: pKa determination for a BAM-HX Brønsted acid. Synlett, 147-149;
34. Singh, A., Yoder, R.A., Shen, B., and Johnston, J.N. (2007) Chiral proton catalysis: enantioselective Brønsted acid catalysed additions of nitroacetic acid derivatives as glycine equivalents. J. Am. Chem. Soc., 129, 3466-3467;
35. Shen, B. and Johnston, J.N. (2008) A formal enantioselective acetate Mannich reaction: the nitro functional group as a traceless agent for the activation and enantiocontrol in the synthesis of ß-amino acids. Org. Lett., 10, 4397-4400.
36. Connon, S.J. (2006) Chiral phosphoric acids: powerful organocatalysts for asymmetric addition reactions to imines. Angew. Chem. Int. Ed., 45, 3909-3912;
37. Akiyama, T. (2007) Stronger Brønsted acids. Chem. Rev., 107, 5744-5758;
38. Adair, G., Mukherjee, S., and List, B. (2008) TRIP-A powerful Brønsted acid catalyst for asymmetric synthesis. Aldrichimica Acta, 41, 31-39;
39. Terada, M. (2008) Binaphthol-derived phosphoric acid as a versatile catalyst for enantioselective carbon-carbon bond forming reactions. Chem. Commun., 4097-4112;
40. Terada, M. (2010) Chiral phosphoric acids as versatile catalysts for enantioselective transformation. Synthesis, 1929-1982;
41. Terada, M. (2010) Chiral phosphoric acids as versatile catalysts for enantioselective carbon-carbon forming reactions. Bull. Chem. Soc. Jpn., 83, 101-119.
42. Etter, M.C. and Panunto, T.W. (1988) 1,3-Bis (m-nitrophenyl)urea: an exceptionally good complexing agent for proton acceptors. J. Am. Chem. Soc., 110, 5896-5897;
43. Etter, M.C., Urbañczyk-Lipkowska, Z., Zia-Ebrahimi, M., and Panunto, T.W. (1990) Hydrogen-bond direct cocrystallization and molecular recognition properties of diarylureas. J. Am. Chem. Soc., 112, 8415-8426;
44. Kelly, T.R. and Kim, M.H. (1994) Relative binding affinity of carboxylate and its isosteres: nitro, phosphate, phosphonate, sulfonate, and ? -lactone. J. Am. Chem. Soc., 116, 7072-7080.
45. Curran, D.P. and Kuo, L.H. (1994) Altering the stereochemistry of allylation reactions of cyclic a-sulfinyl radicals with diarylureas. J. Org. Chem., 59, 3259-3261.
46. Curran, D.P. and Kuo, L.H. (1995) Acceleration of a dipolar Claisen rearrangement by hydrogen bonding to a soluble diaryl urea. Tetrahedron Lett., 36, 6647-6650.
47. Hine, J., Linden, S.-M., and Kanagasabapathy, V.M. (1985) 1,8-Biphenylenediol is a double-hydrogen-bonding catalyst for reaction of an epoxide with a nucleophile. J. Am. Chem. Soc., 107, 1083-1984.
48. Kelly, T.R., Meghani, P., and Ekkundi, V.S. (1990) Diels-Alder reactions: rate acceleration promoted by a biphenylenediol. Tetrahedron Lett., 31, 3381-3384.
49. Bandini, M., Melloni, A., and Umani-Ronchi, A. (2004) New catalytic approaches in the stereoselective Friedel-Crafts alkylation reaction. Angew. Chem. Int. Ed., 43, 550-556;
50. Bandini, M., Melloni, A., Tommasi, S., and Umani-Ronchi, A. (2005) A journey across recent advances in catalytic and stereoselective alkylation of indoles. Synlett, 1199-1222;
51. Bandini, M. and Umani-Ronchi, A. (eds) (2009) Catalytic Asymmetric Friedel-Crafts Alkylations, Wiley-VCH Verlag GmbH, Weinheim.
52. Marqués-López, E., Diez-Martinez, A., Merino, P., and Herrera, R.P. (2009) The role of the indole in important organocatalytic enantioselective Friedel-Crafts alkylation reactions. Curr. Org. Chem., 13, 1585-1609;
53. Terrasson, V., de Figueiredo, R.M., and Campagne, J.M. (2010) Organocatalyzed asymmetric Friedel-Crafts reactions. Eur. J. Org. Chem., 2635-2655.
54. Borschberg, H.-J. (2005) New strategies for the synthesis of monoterpene indole alkaloids. Curr. Org. Chem., 9, 1465-1491;
55. Cacchi, S. and Fabrizi, G. (2005) Synthesis and functionalization of indoles through palladium catalyzed reactions. Chem. Rev., 105, 2873-2920;
56. Poulsen, T.B. and Jørgensen, K.A. (2008) Catalytic asymmetric Friedel-Crafts alkylation reactions-copper showed the way. Chem. Rev., 108, 2903-2915.
57. Dessole, G., Herrera, R.P., and Ricci, A. (2004) H-bonding organocatalysed Friedel-Crafts alkylation of aromatic and heteroatomatic systems with nitroolefines. Synlett, 2374-2378.
58. 2O. Synlett, 1047-1048.
59. Komoto, I. and Kobayashi, S. (2002) 1-Dodecyloxy-4-perfluoroalkylbenzene as a novel efficient additive in aldol reactions and Friedel-Crafts alkylation in supercritical carbon dioxide. Org. Lett., 4, 1115-1118.
60. Alam, M.M., Varala, R., and Adapa, S.R. (2003) Conjugate addition of indoles and thiols with electron-deficient olefins catalyzed by Bi(OTf)3. Tetrahedron Lett., 44, 5115-5119.
61. Bandini, M., Melchiorre, P., Melloni, A., and Umani-Ronchi, A. (2002) A practical indium tribromide catalysed addition of indoles to nitroalkenes in aqueous media. Synthesis, 1110-1114.
62. Bordwell, F.G., Algrim, D.J., and Harrelson, J.A. Jr. (1988) The relative ease of removing a proton, a hydrogen atom, or an electron from carboxamides versus thiocarboxamides. J. Am. Chem. Soc., 110, 5903-5904.
63. Scheerder, J., Engbersen, J.F.J., Casnati, A., Ungaro, R., and Reinhoudt, D.N. (1995) Complexation of halide anions and tricarboxylate anions by neutral urea-derivatized p-tert-butylcalix[6]arenes. J. Org. Chem., 60, 6448-6454.
64. Herrera, R.P., Sgarzani, V., Bernardi, L., and Ricci, A. (2005) Catalytic enantioselective Friedel-Crafts alkylation of indoles with nitroalkenes by using a simple thiourea organocatalyst. Angew. Chem. Int. Ed., 44, 6576-6579.
65. Freeman, S. and Alder, J.F. (2002) Arylethylamine psychotropic recreational drugs: a chemical perspective. Eur. J. Med. Chem., 37, 527-539.
66. Oh, S.J., Ha, H.-J., Chi, D.Y., and Lee, H.K. (2001) Serotonin receptor and transporter ligands-current status. Curr. Med. Chem., 8, 999-1034.
67. Connon, S.J. (2008) Asymmetric catalysis with bifunctional Cinchona alkaloid-based urea and thiourea organocatalysts. Chem. Commun., 2499-2510.
68. Zhuang, W., Hazell, R.G., and Jørgensen, K.A. (2005) Enantioselective Friedel-Crafts type addition of indoles to nitro-olefins using a chiral hydrogen-bonding catalyst-synthesis of optically active tetrahydro- ß-carbolines. Org. Biomol. Chem., 3, 2566-2571.
69. Fleming, E.M., Mccabe, T., and Connon, S.J. (2006) Novel axially chiral bis-arylthiourea-based organocatalysts for asymmetric Friedel-Crafts type reactions. Tetrahedron Lett., 47, 7037-7042.
70. Ganesh, M. and Seidel, D. (2008) Catalytic enantioselective additions of indoles to nitroalkenes. J. Am. Chem. Soc., 130, 16464-16465.
71. Itoh, J., Fuchibe, K., and Akiyama, T. (2008) Chiral phosphoric acid catalyzed enantioselective Friedel-Crafts alkylation of indoles with nitroalkenes: cooperative effect of 3 °A molecular sieves. Angew. Chem. Int. Ed., 47, 4016-4018.
72. Roca-Lopez, D., Sadaba, D., Delso, I., Herrera, R.P., Tejero, T., and Merino, P. (2010) Asymmetric organocatalytic synthesis of γ-nitrocarbonyl compounds through Michael and domino reactions. Tetrahedron: Asymmetry, 21, 2561-2601.
73. Vicario, J.L., Badia, D., and Carrillo, L. (2007) Organocatalytic enantioselective Michael and hetero-Michael reactions. Synthesis, 2065-2092;
74. Tsogoeva, S.B. (2007) Recent advances in asymmetric organocatalytic 1,4-conjugate addition. Eur. J. Org. Chem., 1701-1716;
75. Almaşi, D., Alonso, D.A., and Nájera, C. (2007) Organocatalytic asymmetric conjugate addition. Tetrahedron: Asymmetry, 18, 299-365.
76. Enders, D., Wang, C., and Liebich, J.X. (2009) Organocatalytic asymmetric aza-Michael additions. Chem. Eur. J., 15, 11058-11076;
77. Krishna, P.R., Sreeshailam, A., and Srinivas, R. (2009) Recent advances and applications in asymmetric aza-Michael addition chemistry. Tetrahedron, 65, 9657-9572.
78. Guo, H.-C. and Ma, J.-A. (2006) Catalytic asymmetric tandem transformations triggered by conjugate additions. Angew. Chem. Int. Ed., 45, 354-366.
79. Fernández, R. and Lassaletta, J.M. (2000) Formaldehyde N,N-dialkylhydrazones as C-1 building-blocks in asymmetric synthesis. Synlett, 1228-1240.
80. Marqués-López, E., Herrera, R.P., Fernández, R., and Lassaletta, J.M. (2008) Uncatalyzed Strecker-type reaction of N,N-dialkylhydrazones in pure water. Eur. J. Org. Chem., 3457-3460;
81. Lazny, R. and Nodzewska, A. (2010) N,N-dialkylhydrazones in organic synthesis. From simple N,N-dimethylhydrazones to supported chiral auxiliaries. Chem. Rev., 110, 1386-1434.
82. Sugiura, M. and Kobayashi, S. (2005) N-Acylhydrazones as versatile electrophiles for the synthesis of nitrogen-containing compounds. Angew. Chem. Int. Ed., 44, 5176-5186.
83. Brehme, R., Enders, D., Fernández, R., and Lassaletta, J.M. (2007) Aldehyde N,N-dialkylhydrazones as neutral acyl anion equivalents: umpolung of the imine reactivity. Eur. J. Org. Chem., 5629-5660.
84. Dixon, D.J. and Tillman, A.L. (2005) Enantioselective Brønsted acid catalyzed addition reactions of methyleneaminopyrrolidine to imines. Synlett, 2635-2638;
85. Perdicchia, D. and Jørgensen, K.A. (2007) Asymmetric aza-Michael reactions catalyzed by Cinchona alkaloids. J. Org. Chem., 72, 3565-3568;
86. Rueping, M., Sugiono, E., Theissmann, T., Kuenkel, A., K̈ockritz, A., Pews-Davtyan, A., Nemati, M., and Beller, M. (2007) An enantioselective chiral Brønsted acid catalyzed imino-azaenamine reaction. Org. Lett., 9, 1065-1068;
87. Hashimoto, T., Hirose, M., and Maruoka, K. (2008) Asymmetric imino aza-enamine reaction catalyzed by axially chiral dicarboxylic acid: use of arylaldehyde N,N-dialkylhydrazones as acyl anion equivalent. J. Am. Chem. Soc., 130, 7556-7557.
88. Pettersen, D., Herrera, R.P., Bernardi, L., Fini, F., Sgarzani, V., Fernández, R., Lassaletta, J.M., and Ricci, A. (2006) A broadened scope for the use of hydrazones as neutral nucleophiles in the presence of H-bonding organocatalysts. Synlett, 239-242.
89. Enders, D., Wortmann, L., and Peters, R. (2000) Recovery of carbonyl compounds from N,N-dialkylhydrazones. Acc. Chem. Res., 33, 157-169;
90. Job, A., Janeck, C.F., Bettray, W., Peters, R., and Enders, D. (2002) The SAMP-/RAMP-hydrazone methodology in asymmetric synthesis. Tetrahedron, 58, 2253-2329.
91. Lassaletta, J.-M., Fernández, R., Martín-Zamora, E., and Díez, E. (1996) Enantioselective nucleophilic formylation and cyanation of conjugated enones via Michael addition of formaldehyde SAMP-hydrazone. J. Am. Chem. Soc., 118, 7002-7003;
92. Vazquez, J., Prieto, A., Fernández, R., Enders, D., and Lassaletta, J.M. (2002) Asymmetric Michael addition of formaldehyde N,N-dialkylhydrazones to alkylidene malonates. Chem. Commun., 498-499;
93. Vázquez, J., Cristea, E., Díez, E., Lassaletta, J.M., Prieto, A., and Fernández, R. (2005) Michael addition of chiral formaldehyde N,N-dialkylhydrazones to activated cyclic alkenes. Tetrahedron, 61, 4115-4128.
94. Herrera, R.P., Monge, D., Martín-Zamora, E., Fernández, R., and Lassaletta, J.M. (2007) Organocatalytic conjugate addition of formaldehyde N,N-dialkylhydrazones to ß, ? -unsaturated a-keto esters. Org. Lett., 9, 3303-3306.
95. Ordóñez, M., Rojas-Cabrera, H., and Cativiela, C. (2009) An overview of stereoselective synthesis of a-aminophosphonic acids and derivatives. Tetrahedron, 65, 17-49.
96. Palacios, F., Alonso, C., and de los Santos, J.M. (2005) Synthesis of ß-aminophosphonates and phosphinates. Chem. Rev., 105, 899-931.
97. Merino, P., Marqués-López, E., and Herrera, R.P. (2008) Catalytic enantioselective hydrophosphonylation of aldehydes and imines. Adv. Synth. Catal., 350, 1195-1208.
98. Wang, J., Heikkinen, L.D., Li, H., Zu, L., Jiang, W., Xie, H., and Wang, W. (2007) Quinine-catalyzed enantioselective Michael addition of diphenyl phosphite to nitroolefins: synthesis of chiral precursors of a-substituted ß-aminophosphonates. Adv. Synth. Catal., 349, 1052-1056;
99. Terada, M., Ikehara, T., and Ube, H. (2007) Enantioselective 1,4-addition reactions of diphenyl phosphite to nitroalkenes catalyzed by an axially chiral guanidine. J. Am. Chem. Soc., 129, 14112-14113;
100. Zhu, Y., Malerich, J.P., and Rawal, V.H. (2010) Squaramide-catalyzed enantioselective Michael addition of diphenyl phosphite to nitroalkenes. Angew. Chem. Int. Ed., 49, 153-156.
101. Enders, D., Saint-Dizier, A., Lannou, M.-I., and Lenze, A. (2006) The Phospha-Michael addition in organic synthesis. Eur. J. Org. Chem., 29-49.
102. Bartoli, G., Bosco, M., Carlone, A., Locatelli, M., Mazzanti, A., Sambri, L., and Melchiorre, P. (2007) Organocatalytic asymmetric hydrophosphination of niroalkenes. Chem. Commun., 722-724;
103. Carlone, A., Bartoli, G., Bosco, M., Sambri, L., and Melchiorre, P. (2007) Organocatalytic asymmetric hydrophosphination of a, ß-unsaturated aldehydes. Angew. Chem. Int. Ed., 46, 4504-4506;
104. Ibrahem, I., Rios, R., Vesely, J., Hammar, P., Eriksson, L., Himo, F., and Córdova, A. (2007) Enantioselective organocatalytic hydrophosphination of a, ß-unsaturated aldehydes. Angew. Chem. Int. Ed., 46, 4507-4510;
105. Maerten, E., Cabrera, S., Kjaersgaard, A., and Jørgensen, K.A. (2007) Organocatalytic asymmetric direct phosphonylation of a, ß-unsaturated aldehydes: mechanism, scope, and application in synthesis. J. Org. Chem., 72, 8893-8903.
106. Alcaine, A., Marqués-López, E., Merino, P., Tejero, T., and Herrera, R.P. (2011) Thiourea catalyzed organocatalytic enantioselective Michael addition of diphenyl phosphite to nitroalkenes. Org. Biomol. Chem., 9, 2777-2783.
107. Okino, T., Hoashi, Y., and Takemoto, Y. (2003) Enantioselective Michael reaction of malonates to nitroolefins catalyzed by bifunctional organocatalysts. J. Am. Chem. Soc., 125, 12672-12673;
108. Okino, T., Nakamura, S., Furukawa, T., and Takemoto, Y. (2004) Enantioselective aza-Henry reaction catalyzed by a bifunctional organocatalyst. Org. Lett., 6, 625-627;
109. Okino, T., Hoashi, Y., Furukawa, T., Xu, X., and Takemoto, Y. (2005) Enantio- and diastereoselective Michael reaction of 1,3-dicarbonyl compounds to nitroolefins catalyzed by a bifunctional thiourea. J. Am.Chem. Soc., 127, 119-125.
110. Frisch, M.J., Trucks, G.W., Schlegel, H.B., Scuseria, G.E., Robb, M.A., Cheeseman, J.R., Scalmani, G., Barone, V., Mennucci, B., Petersson, G.A., Nakatsuji, H., Caricato, M., Li, X., Hratchian, H.P., Izmaylov, A.F., Bloino, J., Zheng, G., Sonnenberg, J.L., Hada, M., Ehara, M., Toyota, K., Fukuda, R., Hasegawa, J., Ishida, M., Nakajima, T., Honda, Y., Kitao, O., Nakai, H., Vreven, T., Montgomery, Jr., J.A., Peralta, J.E., Ogliaro, F., Bearpark, M., Heyd, J.J., Brothers, E., Kudin, K.N., Staroverov, V.N., Kobayashi, R., Normand, J., Raghavachari, K., Rendell, A., Burant, J.C., Iyengar, S.S., Tomasi, J., Cossi, M., Rega, N., Millam, N.J., Klene, M., Knox, J.E., Cross, J.B., Bakken, V., Adamo, C., Jaramillo, J., Gomperts, R., Stratmann, R.E., Yazyev, O., Austin, A.J., Cammi, R., Pomelli, C., Ochterski, J.W., Martin, R.L., Morokuma, K., Zakrzewski, V.G., Voth, G.A., Salvador, P., Dannenberg, J.J., Dapprich, S., Daniels, A.D., Farkas, ̈ O., Foresman, J.B., Ortiz, J.V., Cioslowski, J., and Fox, D.J. (2009) Gaussian 09, Revision A.1, Gaussian, Inc., Wallingford CT.
111. Marqués-López, E., Merino, P., Tejero, T., and Herrera, R.P. (2009) Catalytic enantioselective aza-Henry reactions. Eur. J. Org. Chem., 2401-2420.
112. Bernadi, L., Bonini, B.F., Capit ò, E., Dessole, G., Comes-Franchini, M., Fochi, M., and Ricci, A. (2004) Organocatalyzed solvent-free aza-Henry reaction: a breakthrough in the one-pot synthesis of 1,2-diamines. J. Org. Chem., 69, 8168-8171.
113. Ballini, R. and Petrini, M. (2004) Recent synthetic development in the nitro to carbonyl conversion (Nef reaction). Tetrahedron, 60, 1017-1047.
114. Westermann, B. (2003) Asymmetric catalytic aza-Henry reactions leading to 1,2-diamines and 1,2-diaminocarboxylic acids. Angew. Chem. Int. Ed., 42, 151-153;
115. Ting, A. and Schaus, S.E. (2007) Organocatalytic asymmetric Mannich reactions: new methodology, catalyst design and synthetic applications. Eur. J. Org. Chem., 5797-5815.
116. Song, C.E. (ed.) (2009) Cinchona Alkaloids in Synthesis and Catalysis: Ligands, Immobilization and Organocatalysis, Wiley-VCH Verlag GmbH, Weinheim;
117. Marcelli, T. and Hiemstra, H. (2010) Cinchona alkaloids in asymmetric organocatalysis. Synthesis, 1229-1279;
118. Ting, A., Goss, J.M., Mcdougal, N.T., and Schaus, S.E. (2010) Brønsted base catalysts. Top. Curr. Chem., 291, 145-200.
119. Bernardi, L., Fini, F., Herrera, R.P., Ricci, A., and Sgarzani, V. (2006) Enantioselective aza-Henry reaction using Cinchone organocatalysts. Tetrahedron, 62, 375-380.
120. Pettersen, D., Piana, F., Bernardi, L., Fini, F., Fochi, M., Sgarzani, V., and Ricci, A. (2007) Organocatalytic asymmetric aza-Michael reaction: enantioselective addition of O-benzylhydroxylamine to chalcones. Tetrahedron Lett., 48, 7805-7808.