Boron Designer Enzyme with a Hybrid Catalytic Dyad.

Genetically encoded noncanonical amino acids can introduce new-to-nature activation modes into enzymes. While these amino acids can act as catalysts on their own due to their inherent chemical properties, interactions with adjacent residues in an enzyme, such as those present in natural catalytic dyads or triads, unlock a higher potential for designer enzymes. We incorporated a boron-containing amino acid into the protein scaffold RamR to create an active enzyme for the kinetic resolution of α-hydroxythioesters.

Boron catalysis in a designer enzyme.

Enzymes play an increasingly important role in improving the benignity and efficiency of chemical production, yet the diversity of their applications lags heavily behind chemical catalysts as a result of the relatively narrow range of reaction mechanisms of enzymes. The creation of enzymes containing non-biological functionalities facilitates reaction mechanisms outside nature's canon and paves the way towards fully programmable biocatalysis. Here we present a completely genetically encoded boronic-acid-containing designer enzyme with organocatalytic reactivity not achievable with natural or engineered biocatalysts.

AMPA-N - Synthesis and application as standard compound in traceable degradation studies of glyphosate.

Stable isotope labeling of pollutants is a valuable tool to investigate their environmental transport and degradation. For the globally most frequently used herbicide glyphosate, such studies have, so far, been hampered by the absence of an analytical standard for its labeled metabolite AMPA-N, which is formed during the degradation of all commercially available glyphosate isotopologues. Without such a standard, detection and quantitation of AMPA-N, e.

Plasma-Assisted Immobilization of a Phosphonium Salt and Its Use as a Catalyst in the Valorization of CO.

The first plasma-assisted immobilization of an organocatalyst, namely a bifunctional phosphonium salt in an amorphous hydrogenated carbon coating, is reported. This method makes the requirement for prefunctionalized supports redundant. The immobilized catalyst was characterized by solid-state C and P NMR spectroscopy, SEM, and energy-dispersive X-ray spectroscopy.

Reduction of Activated Alkenes by P /P Redox Cycling Catalysis.

The carbon-carbon double bond of unsaturated carbonyl compounds was readily reduced by using a phosphetane oxide catalyst in the presence of a simple organosilane as the terminal reductant and water as the hydrogen source. Quantitative hydrogenation was observed when 1.0 mol % of a methyl-substituted phosphetane oxide was employed as the catalyst.

Organocatalytic Chlorination of Alcohols by P(III)/P(V) Redox Cycling.

A catalytic system for the chlorination of alcohols under Appel conditions was developed. Benzotrichloride is used as a cheap and readily available chlorinating agent in combination with trioctylphosphane as the catalyst and phenylsilane as the terminal reductant. The reaction has several advantages over other variants of the Appel reaction, e.

Intramolecular Base-Free Catalytic Wittig Reaction: Synthesis of Benzoxepinones.

A straightforward two-step synthesis of benzoxepinones was developed via base-free phosphane-catalyzed Wittig reaction. 3-Methyl-1-phenyl-2-phospholene 1-oxide was used as a precatalyst and trimethoxysilane as a reducing agent. Additionally benzoic acid is employed as a catalyst to facilitate the reduction of the phosphane oxide.

Recent Developments in the Synthesis of Cyclic Carbonates from Epoxides and CO.

The use of CO as a C1 building block will be of essential importance in the future. In this context the synthesis of cyclic carbonates from epoxides and CO gained great attention recently. These products are valuable compounds in a variety of chemical fields.