Study On The Titanium-induced Hydrosilation Of Conjugated Diyne And Copper/nickel-induced Synthesis Of Benzene Derivatives

This paper is related to the reactions of alkynes and substituted silane in the presence of metal. Firstly, silicon-containing alkynes were synthesized via hydrosilation induced by titanium. Then hexa-substituted benzenes were prepared via cyclotrimerization with silane-substituted internal alkynes as raw material induced by zirconium.The titanocene-mediated hydrosilation of conjugated diyne by phenyl substituted silane were studied, which afforded novel hydrosilation products of methyl(oct-3-en-5-yn-4-yl)(phenyl)silane and deca-4,6-diene-5,6-diyl bis(phenylsilane) in yields of 34% and 23% respectively and broadened the methodology of hydrosilation.Benzene derivatives are potentially useful in materials, electronic device and biomedicine, among other fields. Directed introduction of substituent onto the phenyl ring with high selectivity to prepare more novel multi-substituted benzene derivatives makes great significance in methodology.A series of hexa-substituted benzenes were synthesized using Negishi reagent. Firstly, a series of zirconacyclopentadienes were synthesized from two silyl-substituted alkynes induced by zirconium. And then reacting with another internal alkyne could afford the corresponding hexa-substituted benzenes. Specifically, 3,6-bis-trimenthylsilanyl-4,5-dimethyl-phthalic acid dimethyl ester(2a), 3,6-bis-tri menthylsilanyl-4,5-dipropyl-phthalic acid dimethyl ester(2b), 3,6-bis-trimenthyl silanyl-4,5-dibutyl-phthalic acid dimethyl ester(2c), 3,6-bis-trimenthyl silanyl-4,5-diphenyl-phthalic acid dimethyl ester(2d), 3,6-bis-trimenthyl silanyl-4,5-diphenyl-phthalic acid diethyl ester(2e) and 3,6-bis- trimenthylsilanyl-4,5- dithienyl-phthalic acid dimethyl ester(2af) could be obtained in yields of 52%, 61% 65%, 45%, 79% and 61% respectively when using DMAD as the third alkyne and induced by copper. Otherwise, 2,5-bis-trimenthylsilanyl-3,4-dimethyl-6-phenyl-N,N-dimethyl benzamide(2g) could be afforded in yield of 62% when using N,N-dimethyl-3-phenylpropiolamide as the third alkyne and induced by Ni. Finally, 3,6-diiodo-4,5-dimethylphthalic acid dimethyl ester(3a), 3,6-diiodo-4,5-dipropyl-phthalic acid dimethyl ester(3b) and 3,6-diiodo-4,5-dibutyl-phthalic acid dimethyl ester(3c) were gained in yields of 85%, 89% and 80% by ipso iododesilylation. We did characterization and analysis of 2d~2g further using FT-IR spectrometer and UV-Vis Spectroscopy.The spatial structures of 3,6-diiodo-phthalic acid dimethyl esters were studied via X-ray analysis. The effects of different substituents on the molecular structure of benzene derivatives with different substituting groups were analyzed and it was concluded that bond lengths of C-I and C-O were influenced by the steric hindrance of substituents on the central benzene ring, the disordered vibration of butyl group had influence on the symmetry of molecule structure. New crystal datas of hexa-substituted benzenes were added by this study.