Selective Hydrogenation of Unsaturated Vinyl Ethers in Two‐Chamber Gauge‐Reactor

A pressure gauge was incorporated into a two‐chamber glass H‐tube to continuously monitor the pressure inside a reactor when working with gases. The ex situ generated H2, D2, acetylene and CO2 were tested in pressure gauge reactors, and calibration curves were plotted. A series of unsaturated compounds with two or more double C=C bonds accessible for hydrogenation were synthesized for hydrogenation. The hydrogenation proceeded well due to constant pressure control, and the desired products were isolated in good yields. The same hydrogenation procedures were then carried out using steel autoclaves to verify the results and compare them. Surprisingly, almost the same results were obtained, confirming the effectiveness of self‐made glass reactors. The hydrogenation mechanism was further investigated using D‐labeled reagents. The kinetics of hydrogenation was studied both in manometric glass reactors and in steel autoclaves, which showed a similar nature of the main process in both reaction units. Thus, the created reactors can be effectively used in barometric transformations instead of steel autoclaves in appropriate cases. Pd‐catalysed hydrogenation of unsaturated vinyl ethers is carried out in self‐made glass reactor with attached pressure gauge. The internal pressure determines the nature of the products: one or two C=C bonds can be hydrogenated. Mechanistic investigations with D‐labeled compounds support hydrogenation from ex situ generated H2 gas. Developed gas reactors can facilitate reactions with gases.