Synthesis and structure of pentasilacycloheptyne

✍ Scribed by Ando Wataru; Nakayama Nobuko; Kabe Yoshio; Shimizu Toshio

• Book ID: 104226539
• Publisher: Elsevier Science
• Year: 1990
• Tongue: French
• Weight: 180 KB
• Volume: 31
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)94452-6

✦ Synopsis

Pentasilacycloheptyne 2 was synthesized by photolysis and thermolysis of hexasilacyclooctyne 1 which was obtained from the reaction of 1,6-&hlomdodecamethylhexasilane with acetylene di-Grignsrd reagent. The molecular structure of 2 was determined by X-my analysis.

Medium ring cycloalkynes have been the subject of considerable interest because there are bond-angle strains on the sp carbons.l Many strained cycloalkynes have been generated as the reactive intermediates and theoretically ~tudied.~ Heterocyclic alkynes were also ~tudied.~ However, few representatives of medium ring polysilacycloalkynes have been so far reported in the literatme.4 We will report here the synthesis of the first molecules of polysilacyclo-monoalkyne namely, hexasilacyclooctyne 1 and pentasilacycloheptyne 2, which am expected to be strain-free by a long Si-Si bond in comparison with the carbon analogue. We will also report the X-ray determined structure of 2.

A reaction of 1,6-dichlorododecamethylhexasilane with acetylene di-Grignard reagent under dilute conditions gave 3,