Enantioselective synthesis phase-transfer catalysis

R Lygo, J. Crosby, J. A. Peterson, Enantioselective Synthesis of Bis-a-Amino Add Esters via Asymmetric Phase-Transfer Catalysis , Tetrahedron Lett. 1999, 40, 1385-1388. 

Jew, Park and coworkers performed systematic investigations to develop a more efficient system for the asymmetric synthesis of a-alkylalanines by chiral phase-transfer catalysis [31]. Eventually, sterically more demanding 2-naphthyl aldi-mine tert-butyl ester 14 was identified as a suitable substrate, and its alkylation in the presence of stronger base rubidium hydroxide (RbOH) and 0(9)-allyl-N-2, 3, 4 -trifluorobenzyldihydrocinchonidinium bromide (6a) at lower reaction temperature led to the highest enantioselectivity (Scheme 2.11). 

Dolling UH, Davis P, Grabowski EJJ (1984) Efficient catalytic asymmetric alkylations, 1. Enantioselective synthesis of (+)-indacrinone via chiral phase-transfer catalysis. J Am Chem Soc 106 446... 

Maruoka K, Ooi T (2003) Enantioselective amino acid synthesis by chiral phase-transfer catalysis. Chem Rev 103 3013-3028... 

Maruoka K, Ooi T. Enantioselective amino acid synthesis by chiral phase-transfer catalysts. Chem. Rev. 2003 103 3013-3028. O Donnell MJ. The enantioselective synthesis of a-amino acids by phase-transfer catalysis with achiral Schiff base esters. Acc. Chem. Res. 2004 37 506-517. 

Reviews on phase-transfer catalysis for the syntheses of a-amino acids, (a) Ooi, T. and Maruoka, K. (2004) Asymmetric organocatalysis of structurally well-defined chiral quaternary ammonium fluorides. Acc. Chem. Res., 37, 526-533 (b) Maruoka, K. and Ooi, T. (2003) Enantioselective amino acid synthesis by chiral phase-transfer catalysis. Chem. Rev., 103, 3013-3028 (c) Ooi, T. and Maruoka, K. (2003) Enantioselective synthesis of a-amino acids by chiral phase-transfer catalysis. Yuki Gosei Kagaku Kyokaishi (J. Synth. Org. Chem.) 61, 1195-1206. 

Enantioselective synthesis of a-amino acids by phase-transfer catalysis with achiral Schiff base esters using Cinchona alkaloids as phase-transfer catalysts 04ACS506. 

Synthesis of amino acids from a Schiff base substrate of glycine, enantioselective alkylation by phase transfer catalysis (PTC) (see 1st edition). 

Scheme 5.9 Enantioselective synthesis (+ )-methyl dihydrojasmonate using enantio-selective phase-transfer catalysis.

O Donnell MJ (2004) The Enantioselective Synthesis of a-Amino Acids by Phase-Transfer Catalysis with Achiral Schijf Base Esters. Acc Chem Res 37 506... 

Dolling, U. H. Davis, R Grabowski, E. J. J. Efficient Catalytic Asymmetric Alkylations. 1. Enantioselective Synthesis of (+)-Indacrinone Via Chiral Phase-Transfer Catalysis. /. Am. Chem. Soc. 1984,106,446-447. 

Scheme 2.18 Enantioselective phase-transfer catalysis synthesis of pyrazolines.

Mahe, O., Dez, L, Levacher, V., Briere, J.-F. (2010). Enantioselective phase-transfer catalysis synthesis of pyrazoUnes. Angewandte Chemie International Edition, 49,7072-7075. 

Ooi, T., Takeuchi, M., Kameda, M., Maruoka, K. (2000). Practical catalytic enantioselective synthesis of a,a-dialkyl-a-amino acids by chiral phase-transfer catalysis. Journal of the American Chemical Society, 122, 5228-5229. 

Enantioselective Synthesis of Optically Pure Amino Acids Phase-Transfer Catalysis... 

Enantioselective oxidation is one of the most important and yet useful transformations in organic synthesis, and the asymmetric phase-transfer catalysis has made notable contributions to this field. The stereoselective epoxidation of electron-deficient olefins with peroxides is a representative example, and Taylor demonstrated the synthetic utility of this system by accomplishing the total syntheses of three natural products of manumycin family, (-l-)-MT 35214 131, (-l-)-manumycin A 132, " and (—)-alisamycin 133 (Scheme 4.31). The syntheses were undertaken by the... 

Perrard T, Plaquevent JC, Desmurs JR, Hebrault D. Enantioselective synthesis of both enantiomers of methyl dihydrojasmo-nate using solid-liquid asymmetric phase-transfer catalysis. Org. Lett. 2000 2(19) 2959-2%2. 

Phase-transfer catalysis is a vast area of organic chemistry, and there are many different examples of the applications of phase-transfer catalysts to asymmetric synthesis, particularly in the area of enantioselective a-ami-noacid synthesis. This area has been extensively reviewed by Maruoka, Lygo and O Donnell. However, there are limited examples where asymmetric phase-transfer catalysis has been applied to drug discovery. One notable example is the asymmetric allylation of glycine imine 337, catalysed by quaternary ammonium bromide 340, which has been used by Kumar et al, as the key step in the synthesis of local anaesthetic levobupivacaine " (339) (Scheme 14.102). 

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