Chemoenzymes

Cp Ir(NHC) complexes are a very versatile type of catalyst, with a wide range of applications. In a chemoenzymatic application, Cp Ir complexes activated by fluo-rinated and nonfluorinated NHC ligands were shown to be catalysts for racemiza-tion in the one-pot chemoenzymic dynamic kinetic resolution (DKR) of secondary... 

Thiem,J. and Sauerbrei, B. (1991) Chemoenzymic synthesis of sialylohgosaccharides with immobilized sialidase. Angevr. Chem. Int. Ed. Engl., 30, 1521-1523. 

Thiem, J. and Wiemann, T. (1990) Combined chemoenzymic structure of A-glycoprotein synthons. Angew. Chem. Int. Ed. 29, 80. 

Nishimura SI, Matsuoka K, Lee YC, Chemoenzymic oligosaccharide synthesis on a soluble polymeric carrier, Tetrahedron Lett., 35 5657-60, 1994. 

Paedragosa-Moreau, S., Morisseau, C., Baratti, J., Zylber, J., Archelas, A., and Furstoss, R. 1997. Microbiological transformations. 37. An enantioconvergent synthesis of the (l-blocker (R)-Nifenalol using a combined chemoenzymic approach. Tetrahedron, 53(28), 9707-9714. 

Gavagan, J.E., Eager, S.K., Eallon, R.D., et al. 1998. Chemoenzymic production of lactams from aliphatic a,co-dinitriles. Journal of Organic Chemistry, 63 4792 801. 

Unverzagt, C, Chemoenzymic s3mthesis of a sialylated diantennary A-glycan linked to asparagine, Carbohydr. Res., 305, 423-431, 1998. 

Chemoenzymic synthesis of giycopeptide iibrary by Nishimura and co-workers... 

Mahmoudian M, Dawson MJ (1997) Chemoenzymic production of the antiviral agent... 

Li S-M (2009) Prenylated indole derivatives from fungi structure diversity, biological activities, biosynthesis and chemoenzymic synthesis. Nat Prod Rep 27 57-78... 

A comprehensive review (260 refs.) on the synthesis of carbohydrates from noncarbohydrate sources covers the use of benzene-derived diols and products of Sharpless asymmetric oxidation as starting materials, Dodoni s thiazole and Vogel s naked sugar approaches, as well as the application of enzyme-catalysed aldol condensations. The preparation of monosaccharides by enzyme-catalysed aldol condensations is also discussed in a review on recent advances in the chemoenzymic synthesis of carbohydrates and carbohydrate mimetics, in parts of reviews on the formation of carbon-carbon bonds by enzymic asymmetric synthesis and on carbohydrate-mediated biochemical recognition processes as potential targets for drug development, as well as in connection with the introduction of three Aldol Reaction Kits that provide dihydroxyacetone phosphate-dependent aldolases (27 refs.). A further review deals with the synthesis of carbohydrates by application of the nitrile oxide 1,3-dipolar cycloaddition (13 refs.). ... 

A review on the chemoenzymic synthesis of carbohydrates and carbohydrate mimetics features the use of aldolases in the synthesis of neuraminic acid and KDO analogues. ... 

Chemoenzymic methods have been used to make polyoxyalkyl dendimers carrying six copies of p-5-linked p-o-Lac and -P-d-G1cNAc which were used as precursors for the synthesis of lactose 3 -sulfate (chemical methods) and LacNAc (enzymic methods), respectively. " ... 

Compounds of this set to have been prepared are 46, a core fucosylated, bianten-nary N-glycan with a novel GlcNAc residue in the core region, 47, a Sia Le containing compound with and without a sulfate ester at 0-6 of the GlcNAc residue, and 48 made by chemoenzymic methods and linked to a fluorophore to provide means of visualization of cell-surface selectively bound SiaLe compounds. ... 

The chemoenzymic synthesis of trimeric SiaLe decasaccharide 49 was achieved by enzymically sialylating and fucosylating the linear hexamer. The analogue... 

Dordick JS (1992b) Enzymic and chemoenzymic approaches to polymer synthesis. Trends Technol 10 287-293... 

Amino acid surfactants (AAS), both natural and synthetic types, have been the subject of many smdies, due mostly to their huge potential application in pharmaceutical, cosmetic, household, and food products. The AAS are derived from acidic, basic, or neutral amino acids. Amino acids such as glutamic acid, glycine, alanine, arginine, aspartic acid, leucine, serine, proline, and protein hydrolysates have been used as starting materials to synthesize AAS commercially and experimentally. Methods of preparation include chemical, enzymatic, and chemoenzymic processes, although chemical processes have been prevalent due to their relatively low cost of production. In recent years, more research papers have focused on the use of enzymatic methods to synthesize AAS. It is our opinion that the enzymatic approach would be more attractive to manufacturers in the near future. 

A number of reviews on the chemical synthesis of fluorinated carbohydrates have been published, as well as others covering the chemoenzymic synthesis of fluorosugars, the preparation and reactions of glycosyl fluorides, and the preparation of F-deo3 uorohexoses7... 

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