Complete Field Guide to Asymmetric BINOL-Phosphate Derived Brønsted Acid and Metal Catalysis: History and Classification by Mode of Activation; Brønsted Acidity, Hydrogen Bonding, Ion Pairing, and Metal Phosphates

Based on the principles and metrics of green chemistry and sustainable development, biocatalysis is both a green and sustainable technology. This is largely a result of the spectacular advances in molecular biology and biotechnology achieved in the past two decades. Protein engineering has enabled the optimization of existing enzymes and the invention of entirely new biocatalytic reactions that were previously unknown in Nature. It is now eminently feasible to develop enzymatic transformations to fit predefined parameters, resulting in processes that are truly sustainable by design. This approach has successfully been applied, for example, in the industrial synthesis of active pharmaceutical ingredients. In addition to the use of protein engineering, other aspects of biocatalysis engineering, such as substrate, medium, and reactor engineering, can be utilized to improve the efficiency and cost-effectiveness and, hence, the sustainability of biocatalytic reactions. Furthermore, immobilization of an enzyme ...

/pdf/role-of-biocatalysis-in-sustainable-chemistry-5b3e0qe0ep.pdf

Role of Biocatalysis in Sustainable Chemistry

Catalytic Enantioselective Formation of C−C Bonds by Addition to Imines and Hydrazones: A Ten-Year Update

The review examines the chiral amine literature from 2000-2009 (May) concerning enantioselective and diastereoselective methods for N-acylenamide and enamine reduction, reductive amination, and imine reduction. The reaction steps for each strategy, from ketone to primary chiral amine, are clearly defined, with best methods and yields for starting material preparation and final deprotection noted. Categories of chiral amines have been defined in Section 1 to allow the reader to quickly understand whether their specific target amine falls within a difficult to synthesize, or not, structural class. Amino acids are not considered in this work.

Chiral Amine Synthesis – Recent Developments and Trends for Enamide Reduction, Reductive Amination, and Imine Reduction

Asymmetric Organocatalytic Cyclization and Cycloaddition Reactions

The asymmetric Mannich reaction ranks among the most potent enantioselective and diastereoselective C–C-bond forming reactions. In recent years, organocatalysed versions of asymmetric Mannich processes have been increasingly reported and used in a rapidly growing number of applications. This tutorial review provides an overview of the recent history of the asymmetric organocatalysed Mannich reaction, including scope and limitations, and application of different catalyst systems.

Organocatalysed asymmetric Mannich reactions.

Mild and efficient deprotection of the amine protecting p-methoxyphenyl (PMP) group

Herein, we report a new flow process with immobilized enzymes to synthesize complex chiral carbohydrate analogues from achiral inexpensive building blocks in a three-step cascade reaction. The first reactor contained immobilized acid phosphatase, which phosphorylated dihydroxyacetone to dihydroxyacetone phosphate using pyrophosphate as the phosphate donor. The second flow reactor contained fructose-1,6-diphosphate aldolase (RAMA, rabbit muscle aldolase) or rhamnulose-1-phosphate aldolase (RhuA from Thermotoga maritima) and acid phosphatase. The immobilized aldolases coupled the formed dihydroxyacetone phosphate to aldehydes, resulting in phosphorylated carbohydrates. A final reactor containing acid phosphatase that dephosphorylated the phosphorylated product yielded the final product. Different aldehydes were used to synthesize carbohydrates on a gram scale. To demonstrate the feasibility of the flow systems, we synthesized 0.6 g of the D-fagomine precursor. By using immobilized aldolase RhuA we were also able to obtain other stereoisomers of the D-fagomine precursor.

Synthesis of carbohydrates in a continuous flow reactor by immobilized phosphatase and aldolase

https://repository.ubn.ru.nl/bitstream/handle/2066/92396/92396.pdf

Synthesis of non-natural carbohydrates from glycerol and aldehydes in a one-pot four-enzyme cascade reaction

A novel enzymatic procedure for the oxidative deprotection of p-methoxyphenyl (PMP)-protected amines is described. By using laccases (E.C. 1.10.3.2) under mildly acidic conditions, a variety of PMP-protected amines were successfully deprotected. The rate of deprotection was solvent- and pH-dependent, and the reaction scope could be increased by using so-called mediators.

Lieke J. C. van Hemert

Papers

Organocatalysed asymmetric Mannich reactions.

Mild and efficient deprotection of the amine protecting p-methoxyphenyl (PMP) group

Synthesis of carbohydrates in a continuous flow reactor by immobilized phosphatase and aldolase

Synthesis of non-natural carbohydrates from glycerol and aldehydes in a one-pot four-enzyme cascade reaction

Laccase‐Mediated Deprotection of para‐Methoxyphenyl (PMP)‐Protected Amines