Selective Synthesis of Functional Alkynylmono‐ and ‐trisilanes

The selective synthesis of functional alkynylsilanes RC≡C–(SiMe 2 ) m –X ( m = 1, 3) was investigated. Monofunctionalization with or without protecting groups gave moderate to good yields of alkynyldimethylmonosilanes RC≡CMe 2 SiX [R = Ph, X = Cl ( 1 ), NEt 2 ( 2 ), OMe ( 3 ), H ( 4 ), Br ( 5 ), I ( 6 ), Cp ( 8 ), C 5 H 4 Li ( 10 ), Ph ( 11 ); R = Pr, X = Ph ( 12 )]. Compounds 4 and 8 were converted into the (alkyne)transition‐metal complexes 4· Cp 2 Mo 2 (CO) 4 ( 13 ) and 8· Co 2 (CO) 6 ( 14 ), respectively, which were characterized by X‐ray diffraction. Stepwise extension and functionalization of the silane chain starting from 1‐chloro‐2‐(diethylamino)tetramethyldisilane (Et 2 NMe 2 Si–SiMe 2 Cl) yielded the trisilanes Ph–(SiMe 2 ) 3 –X [X = NEt 2 ( 18 ), OMe ( 19 ), Cl ( 20 ), H ( 21 ), C≡CPh ( 22 ), C≡CPr ( 23 )]. The synthesized compounds were characterized by NMR and IR spectroscopy, 4 , 11 , 13 , and 14 also by UV/Vis spectroscopy.