Chain elongation of unprotected carbohydrates in water under mild conditions remains a challenge both in chemical and biochemical synthesis. The Knoevenagel addition or condensation enables transformations to bioactive scaffolds for pharmaceutical and agrochemical compounds. Unfortunately, the catalysts in use for these transformations often reduce the green metrics of the transformations.
View Article and Find Full Text PDFWe describe a concise synthetic strategy for the preparation of heterocyclic [9]helicenes and a simple preparative-scale protocol for the optical resolution of the resulting M- and P-enantiomers. The helicenes were characterized by single-crystal X-ray diffraction along with a range of spectroscopic and computational techniques. A fluorescence quantum yield of up to 65 % was observed, and the chiroptical properties of both M- and P-helicenes revealed large dissymmetry factors.
View Article and Find Full Text PDFMany enzymes have latent activities that can be used in the conversion of non-natural reactants for novel organic conversions. A classic example is the conversion of benzaldehyde to a phenylacetyl carbinol, a precursor for ephedrine manufacture. It is often tacitly assumed that purified enzymes are more promising catalysts than whole cells, despite the lower cost and easier maintenance of the latter.
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