A new practical preparation method for Lanthanum-Lithium-Binaphthol catalysts (LLBs) for use in asymmetric nitroaldol reactions

Enantiomer

Volumn 2, Issue 3-4, 1997, Pages 267-271

  Sasai, Hiroaki ^a   Watanabe, Shizue ^a   Shibasaki, Masakatsu ^a  

^a UNIVERSITY OF TOKYO   (Japan)

Author keywords

Asymmetric Catalyst; Asymmetric Nitroadol Reaction; Lanthanum Lithium Binaphthol Catalyst; Lanthanum lithium Binaphthol Derivative Complexes; Syn selectivity

Indexed keywords

LANTHANUM; LITHIUM; NAPHTHOL DERIVATIVE; NITROALKANE; NITROMETHANE;

CATALYSIS; CHEMICAL REACTION; CONFERENCE PAPER; DRUG SYNTHESIS; NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY; PRIORITY JOURNAL; STEREOCHEMISTRY;

EID: 0030757292     PISSN: 10242430     EISSN: None     Source Type: Journal    
DOI: None     Document Type: Conference Paper

References (12)

1. (a) Sasai, H., Suzuki, T., Arai, S., Arai, T. and Shibasaki, M., (1992). J. Am. Chem. Soc., 114, 4418-4420.
2. (b) Sasai, H., Suzuki, T., Itoh, N. and Shibasaki, M. (1993). Tetra-hedron Lett., 34, 851-554.
3. (c) Sasai, H., Itoh, N., Suzuki, T. and Shibasaki, M. (1993). Tetrahedron Lett., 34, 855-858.
4. (d) Sasai, H., Suzuki, T., Itoh, N., Arai, S. and Shibasaki, M. (1993). Tetrahedron Lett., 34, 2657-2660.
5. (e) Sasai, H., Suzuki, T., Itoh, N., Tanaka, K., Date, T., Okamura, K. and Shibasaki, M. (1993). J. Am. Chem. Soc., 115, 10372-10373.
6. (f) Sasai, H., Kim, W.-S., Suzuki, T., Shibasaki, M., Mitsuda, M., Hasegawa, J. and Ohashi, T. (1994). Tetrahedron Lett., 35, 6123-6126.
7. (g) Sasai, H., Yamada, Y. M. A., Suzuki, T. and Shibasaki, M. (1994). Tetrahedron, 50, 12313-12318.
8. Sasai, H., Tokunaga, T., Watanabe, S., Suzuki, T., Itoh, N. and Shibasaki, M. (1995). J. Org. Chem., 60, 7388-7389.
9. 2O-derived LLB, the nitroaldol reaction of cyclohexanecarboxaldehyde with nitromethane (10 equiv) at -50°C afforded the adduct with 88% ee. Binaphthol was completely recovered, without racemization, after completion of the reaction.
10. Dilithium bis(triethylsilylethynyl)binaphthoxide was generated at -78°C
11. Cf. reference [2]: 97% ee, 21% yield, syn-.anti = 16:1.
12. For the equilibrium acidities of nitroalkanes see: Bordwell, F. G. and Bartmess, E. (1978). J. Org. Chem., 43, 3101-3107.