Sodium hydroxide manufacturers said that noble metal catalysis plays a leading role in the traditional C-H bond activation. The use of precious metals increases the cost and limits the practical application of C-H bond activation. Therefore, people have been trying to find a large number of cheap and easily available main group metals to realize the activation of C-H bond. In 2015, professor Brian Stoltz and Professor Robert Grubbs reported on nature that kotbu was used to catalyze the silylation of sp2C-H bond of aromatic heterocycles, which attracted the general attention of chemists. In view of the important application of alkynyl silicon compounds in organic synthesis, the team considered extending the system to the preparation of alkynyl silicon compounds.
The traditional preparation of alkynyl silicon compounds commonly used by sodium hydroxide manufacturers starts from terminal alkynes, which mainly includes the following two routes (scheme 1a): alkali pulls out protons and attacks electrophilic si-x species to obtain alkynyl silicon (route a); Transition metal catalyzed direct silylation of alkynes (route b). In recent years, it has been found that MgO, liah4 and even alkoxides also show catalytic activity in the dehydrogenation coupling of terminal alkynes with silyl hydrogen species. However, the limitations of these substrates are large, the yield and selectivity are medium, and the reaction temperature is also high, which reduces the applicability.
Importantly, although there are reports of silylation of heterocyclic alkynes using expensive cf3tms, most heterocyclic or aliphatic amine containing terminal alkynes cannot participate in the reaction. Here, sodium hydroxide manufacturers have realized a simple, efficient and universal methodology for dehydrogenation coupling of terminal alkynes and silicon hydrogen. Surprisingly, the catalyst used by sodium hydroxide manufacturers is the ubiquitous NaOH or KOH.