Stereoselective amino acid synthesis by photobiocatalytic oxidative coupling.

Photobiocatalysis-where light is used to expand the reactivity of an enzyme-has recently emerged as a powerful strategy to develop chemistries that are new to nature. These systems have shown potential in asymmetric radical reactions that have long eluded small-molecule catalysts. So far, unnatural photobiocatalytic reactions are limited to overall reductive and redox-neutral processes.

Enzymes on Steroids.

Efficient assembly and functionalization of biologically active steroids continue to pose a significant synthetic hurdle. The mining and engineering of selective P450 C-H hydroxylases combined with chemoenzymatic synthesis furnished a new solution to this challenging problem.

Practical Biocatalytic Synthesis of Aromatic Nitriles.

Aromatic nitriles are important building blocks with wide applications in pharmaceutical and agrochemical industries as well as materials science. In a recent paper, Gröger and coworkers engineered aliphatic aldoxime dehydratases (Oxds) for the scalable synthesis of aromatic nitriles, delivering a sustainable and energy-efficient technology for the manufacturing of aromatic nitriles.

Stereoselective amino acid synthesis by synergistic photoredox-pyridoxal radical biocatalysis.

Developing synthetically useful enzymatic reactions that are not known in biochemistry and organic chemistry is an important challenge in biocatalysis. Through the synergistic merger of photoredox catalysis and pyridoxal 5'-phosphate (PLP) biocatalysis, we developed a pyridoxal radical biocatalysis approach to prepare valuable noncanonical amino acids, including those bearing a stereochemical dyad or triad, without the need for protecting groups. Using engineered PLP enzymes, either enantiomeric product could be produced in a biocatalyst-controlled fashion.

Highly Selective and Catalytic Generation of Acyclic Quaternary Carbon Stereocenters via Functionalization of 1,3-Dienes with CO.

The catalytic asymmetric functionalization of readily available 1,3-dienes is highly important, but current examples are mostly limited to the construction of tertiary chiral centers. The asymmetric generation of acyclic products containing all-carbon quaternary stereocenters from substituted 1,3-dienes represents a more challenging, but highly desirable, synthetic process for which there are very few examples. Herein, we report the highly selective copper-catalyzed generation of chiral all-carbon acyclic quaternary stereocenters via functionalization of 1,3-dienes with CO.

Transition metal-free phosphonocarboxylation of alkenes with carbon dioxide via visible-light photoredox catalysis.

Catalytic difunctionalization of alkenes has been an ideal strategy to generate structurally complex molecules with diverse substitution patterns. Although both phosphonyl and carboxyl groups are valuable functional groups, the simultaneous incorporation of them via catalytic difunctionalization of alkenes, ideally from abundant, inexpensive and easy-to-handle raw materials, has not been realized. Herein, we report the phosphonocarboxylation of alkenes with CO via visible-light photoredox catalysis.