Silylation of phenylacetylene with trimethylchlorosilane (TMCS) in the presence of zinc powder catalyst will produce around 33% alkene by-product. Different organic additives were used as H scavengers to reduce the production of styrene (ST). From the results via GC analysis

pyridine and 1

8-diazabicyclo[5.4.0]undec-7-ene(DBU) were found to be effective to increase the selectivity but the conversion rate was decreased. The concentration of organic additives

reaction time and temperature were then optimized. The concentration optimization showed that 6 mol DBU was effective to decrease the generation of styrene but the yield of main product phenylethynyltrimethylchlorosilane (PT) dropped significantly. 6 mol pyridine was the optimal concentration for its relatively high conversion and selectivity. The yield of styrene decreased to around 13% while the yield of PT was 57%. The optimal reaction time was 20 h. Conversion and selectivity rarely changed with a longer reaction time. As for temperature

it was found that a higher temperature was beneficial to improve the conversion but unfavorable to selectivity. The results showed that the conversion was highest at 110℃ while the selectivity was best at 100℃ with 6 mol pyridine.