Automated On-Demand Titration of Organometallic Reagents in Continuous Flow

Abstract

The use of strong organometallic bases and nucleophiles is commonplace in modern organic synthesis. That they react with a wide range of functional groups requires accurate and precise stoichiometry in reactions that utilize them. For best results, these bases are titrated prior to use, and such titrations can be timeconsuming and variable due to human error near the end point. Herein, we describe an automated method for titrations of multiple commercial organometallic reagents enabled by continuous flow. Through utilizations of continuous monitoring via UV−vis spectroscopy and a feedback loop developed within LabVIEW, titrations with enhanced reproducibility were provided over current batch procedures.

Precise NMR Method for Titering Organometal Reagents

“…Considering that reagent utility centers on accurate concentrations, it is important to periodically, if not prior to every use, evaluate the concentration by some form of titration. Numerous experimental titrating methods for determining the concentration of organometal reagents provide satisfactory results, although the time-consuming and tedious task discourages routine evaluation. Another drawback is that most experimental methods use specific indicators for certain reagent/solvent pairs, and importantly, the end-point observation is prone to operator error.…”

Convenient and accurate insight into solution-phase equilibria from FlowNMR titrations

“…1). With simple feedback loops automated titration setups have even been realised, both on lab 15,16 and process scales. 17,18…”

“…1). With simple feedback loops automated titration setups have even been realised, both on lab 15,16 and process scales. 17,18 The use of a closed-loop flow system through a high-field NMR spectrometer may combine the advantages of the high specificity and information content of high-resolution NMR with the convenience and accuracy of simple in situ pH probes.…”

Fluoride-triggered phase transition of metallogels for on-demand in situ containment of fluids

“…Fluidic systems are widely employed across multiple disciplines, such as flow chemistry, 1 biomedical engineering, 2 and environmental monitoring. 3 The configurational flexibility and operational simplicity of flow systems enable functions beyond the limitations of conventional closed systems, such as continuous reaction, 4 high throughput, 2 b,c ,5 safer operation, 6 automated monitoring, 5 a ,7 and integration with analytics. Given their significance, considerable research efforts have been directed toward monitoring the flow by external sensors.…”