Crystal Structure of a Dewar Benzene Derivative Formed from Fluoro(triisopropylsilyl)acetylene

Abstract

Spontane Trimerisierung von Fluor(triisopropylsilyl)acetylen, das aus 1,1‐Difluorethylen in einem Schritt erhalten wird, liefert das entsprechende fluorierte Dewar‐Benzol‐Derivat, dessen Struktur durch Röntgenbeugung ermittelt wurde (siehe Bild).

Enamine N-Oxides: Design, Synthesis, and Function in Bioortho­gonal Reactions

“…38 39 Capitalizing on an atom’s propensity to rehybridize bonding orbitals directed toward an electronegative substituent to a lower s-character state as dictated by Bent’s rule, 40 we decided to explore the effect of using terminally halogenated alkynes in the retro-Cope elimination reaction. Computational studies on the Bergman cyclization by Alabugin and co-workers 41 as well as experimental observations describing the rapid trimerization of 1-fluoroalkynes 42 supported our hypothesis that the rehybridization effect could be a powerful driving force for the hydroamination reaction. Indeed, reaction of 6-chlorohex-5-yn-1-ol ( 10 ) with N , N -diethylhydroxylamine progressed to nearly full conversion and 61% yield in 24 hours, whereas its unhalogenated counterpart hex-5-yn-1-ol ( 12 ) only reached partial conversion and 41% yield over 10 days (Scheme 1 ).…”