New approaches to heck reaction testing for homogeneity-heterogeneity

Modified catalytic reaction tests for homogeneity-heterogeneity are proposed. In these tests, the time dependence of a reaction response (conversion, product yield, or selectivity) to various manipulations used in traditional tests rather than the suppression or retention of catalytic activity (positive or negative test results) is of crucial importance. With the use of the Heck reaction as an example, it is demonstrated that the results of these modified and traditional tests can lead to opposing conclusions. In this case, the results of the modified tests are consistent with each other and with the results of studies on the kinetics and selectivity of the reaction, as well as with a great body of other experimental data published in the past five to seven years, which are indicative of the true homogeneous character of the Heck reaction.