21. In this regard the diazo -thioketone coupling is a cross-coupling rather than a homocoupling. 22. His thesis was " A Study of the Possible Asymmetry of Aliphatic Diazo Compounds ". 23. With ammonia, one obtains 2-chloro-4-nitroaniline, a precursor to diazo dyes. 24. Huisgen investigated a series of cycloadditions between the 1, 3-dipolar diazo compounds and various dipolarophilic alkenes. 25. Related diazo compounds behave similarly, e . g . 1, 1'- azobis ( cyclohexanecarbonitrile ). 26. :: : Then, later ( but still before Xerographic copiers ), diazo copiers came into use. 27. "' Kinamycin "'is a group of bacterial polyketide secondary metabolites containing a diazo group. 28. Diazoketones are typically generated as described here, but other methods such as diazo -group transfer can also apply. 29. Prof . Nesmeyanov had discovered the reaction of diazo -compounds with metal halides which was later named after him. 30. In archival practice, Diazo prints are the most common reprographic format encountered in late 20th-century architectural collections.
