Legion: An Instrument for High-Throughput Electrochemistry.

Electrochemical arrays promise utility for accelerated hypothesis testing and breakthrough discoveries. Herein, we report a new high-throughput electrochemistry platform, colloquially called "Legion," for applications in electroanalysis and electrosynthesis. Legion consists of 96 electrochemical cells dimensioned to match common 96-well plates that are independently controlled with a field-programmable gate array.

Cobalamin-Mediated Electrocatalytic Reduction of Ethyl Chloroacetate in Dimethylformamide.

The catalytic reduction of ethyl chloroacetate (ECA) by hydroxocobalamin (HOCbl) in dimethylformamide was studied electrochemically and spectroelectrochemically to identify initial steps in the reaction between the electrogenerated Co(I) center of cobalamin (cob(I)alamin) and ECA. Cyclic voltammograms of HOCbl in the presence of ECA show a small increase in current related to reduction of Co(II) to Co(I), and a new peak at more negative potentials related to reduction of an ethyl carboxymethyl-Cbl intermediate. The oxidation state of HOCbl during catalysis was monitored by means of spectroelectrochemical controlled-potential bulk electrolysis.

Controlling Non-Native Cobalamin Reactivity and Catalysis in the Transcription Factor CarH.

Vitamin B derivatives catalyze a wide range of organic transformations, but B-dependent enzymes are underutilized in biocatalysis relative to other metalloenzymes. In this study, we engineered a variant of the transcription factor CarH, called CarH*, that catalyzes styrene C-H alkylation with improved yields (2-6.5-fold) and selectivity relative to cobalamin.

Versatile Tools for Understanding Electrosynthetic Mechanisms.

Electrosynthesis is a popular, green alternative to traditional organic methods. Understanding the mechanisms is not trivial yet is necessary to optimize reaction processes. To this end, a multitude of analytical tools is available to identify and quantitate reaction products and intermediates.