Enantioselective 1,3-Dipolar Cycloadditions of Azlactones and Electrophilic Alkenes Catalyzed by Dimeric BinapAuTFA Complexes

Abstract

Glycine-derived azlactones react with maleimides using (S)- or (R)-dimeric BinapAuTFA complexes affording the corresponding cycloadducts in good yields and high enantioselections (up to 99% ee). The intermediate carboxylic acids are treated with trimethylsilyldiazomethane and isolated as Δ^¹-pyrroline methyl esters. These cycloadducts are transformed into exo-proline derivatives by reduction with NaBH₃CN in acidic media. On the other hand, N-benzoylalanine-derived oxazolone reacts with tert-butyl acrylate providing the cycloadduct with the ester group at the 3-position with a trans-relative configuration with respect to the methyl ester group.

gold - Binap - cycloaddition - azomethine ylides - asymmetric catalysis

References and Notes

For recent reviews about general 1,3-DC, see:

1a Padwa A. Pearson WH. In Synthetic Applications of 1,3-Dipolar Cycloaddition Chemistry Towards Heterocycles and Natural Products   John Wiley & Sons; New Jersey: 2003. 

1b Nájera C. Sansano JM. Curr. Org. Chem.  2003,  7:  1105 

1c Nair V. Suja TD. Tetrahedron  2007,  63:  12247 

1d Padwa A. Bur SK. Tetrahedron  2007,  63:  5341 

1e Pellissier H. Tetrahedron  2007,  63:  3235 

For reviews dealing with enantioselective 1,3-DC, see:

2a Nájera C. Sansano JM. Top. Heterocycl. Chem.  2008,  12:  117 

2b Stanley LM. Sibi MP. Chem. Rev.  2008,  108:  2887 

2c Álvarez-Corral M. Muñoz-Dorado M. Rodríguez-García I. Chem. Rev.  2008,  108:  3174 

2d Naodovic M. Yamamoto H. Chem. Rev.  2008,  108:  3132 

2e Nájera C. Sansano JM. Yus M. J. Braz. Chem. Soc.  2010,  21:  377 

2f Kissane M. Maguire AR. Chem. Soc. Rev.  2010,  39:  845 

3a Nájera C. Sansano JM. Org. Biomol. Chem.  2009,  7:  4567 

3b Nájera C. Sansano JM. Monatsh. Chem.  2011,  142:  659 

4a Ma D. Yang J. J. Am. Chem. Soc.  2001,  123:  9706 

4b Hughes CC. Trauner D. Angew. Chem. Int. Ed.  2002,  41:  4556 

4c Kleinsasser NH. Wallner BC. Harreus UA. Zwickenpflug W. Richter E. Toxicology  2003,  192:  171 

4d Stapon A. Li R. Townsend CA. J. Am. Chem. Soc.  2003,  125:  8486 

5 Fisk JS. Mosey RA. Tepe JJ. Chem. Soc. Rev.  2007,  36:  1432 

6a Karoyan P. Sagan S. Lequin O. Quancard J. Lavielle S. Chassaing G. Targets Heterocycl. Syst.  2004,  8:  216 

6b Nájera C. Sansano JM. Chem. Rev.  2007,  107:  4586 

6c Calaza MI. Cativiela C. Eur. J. Org. Chem.  2008,  3427 

6d Asymmetric Synthesis and Applications of α-Amino Acids   Soloshonok VA. Izawa K. American Chemical Society; Washington DC: 2009. 

7 Alba A.-NR. Ríos R. Chem. Asian J.  2011,  6:  720 

8 Peddibhothla S. Tepe JJ. J. Am. Chem. Soc.  2004,  126:  12776 

9a Melhado AD. Luparia M. Toste FD. J. Am. Chem. Soc.  2007,  129:  12638 

9b Melhado AD. Amarante GW. Wang J. Luparia M. Toste FD. J. Am. Chem. Soc.  2011,  133:  3517 

10a Martín-Rodríguez M. Nájera C. Sansano JM. Wu FL. Tetrahedron: Asymmetry  2010,  21:  1184 ; corrigendum: Tetrahedron: Asymmetry 2010, 21, 2559

10b

Martín-Rodríguez, M.; Nájera, C.; Sansano, J. M.; de Cózar, A.; Cossío, F. P. submitted for publication

10c Martín-Rodríguez M. Nájera C. Sansano JM. de Cózar A. Cossío FP. Beilstein J. Org. Chem.  2011,  7:  988 

For recent reviews, including recent examples of the use of [(AuX)₂(P-P)*] complexes in catalysis, see:

11a Hashmi ASK. Chem. Rev.  2007,  107:  3180 

11b Wiedenhoefer RA. Chem. Eur. J.  2008,  14:  5382 

11c Gorin DJ. Sherry BD. Toste FD. Chem. Rev.  2008,  108:  3351 

11d Sengupta S. Shi X. ChemCatChem  2010,  2:  609 

12 Wheaton CA. Jennings MC. Puddephatt RJ. Z. Naturforsch., B  2009,  64:  1469 

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For the typical procedure and data of the isolated products, see Supporting Information.