Silyl-proton exchange reactions

Abstract

Similar trends are not observed in other petroleum families. In each case a three-ring structure is preferred, and this recalls the presence of the tetrahydroor hexahydrocarbazole nucleus in certain alkaloids (e.g., aspidospermine (33). Again it seems likely that a preference for a given structure in petroleum is rooted in a similar preference for that structure in plants.A detailed examination of the structural relationships between individual N,0 compounds and their precursors in nature will be presented elsewhere.24 (24) G. C. Speers and E. V. Whitehead, "Crude Petroleum. Organic Geochemistry: Methods and Results," Springer-Verlag, New York, N. Y., in press.

Über die Reaktion des Tris‐(trimethylsilyl)‐silyllithiums mit Aceton

“…I R (Nujol): 2075 cm-l (Si-H). IH-NMR: 6 = 3,33 pprn (5, SiH, IH); 1,48 pprn (5, CCH,, 6H); 0,24 ppm (5, SiSi(CH,),, 1XH); 31s: m/e = 291 (1,53%, M-CHJ; 233 (11,57%, M-SiMe,); 217 (7,93y0,); l:31 0.15 ppm (s, OSi(CH,),, 9H).…”

“…C,,H,,CISi, (499,7),C 43,40 (ber. 43,26); H 10,47 (1029); CI 6,95(7,09)%. I R (Nujol): 460 cm-l (Si-Cl).…”

Strong influence of intramolecular Si⋯O proximity on reactivity: Systematic molecular structure, solvolysis, and mechanistic study of cyclic N -trimethylsilyl carboxamide derivatives

“…6 One of the first reports concerning the unique reactivity of silylated amides, for example, over silyl amines, was published by Klebe who presumed a switch from the pentacoordinated configuration of the silicon center to the hexacoordinated one upon nucleophilic attack by a proton donor onto the Si atom. 7 In a later study, Lane and Frye determined the relative thermodynamic silylating abilities of trimethylsilylated N-alkyl amides and observed significantly different stability for the silylated pyrrolidone and ε-caprolactam, respectively; however this phenomenon was not fully rationalized. 8 Figure 1.…”

Atom efficient synthesis of pyrimidine and purine nucleosides by ball milling

“…11 The silylation was conducted using hexamethyldisilazane (HMDS) according to standard literature procedures. This is thought to enhance the lipophilicity and nucleophilicity of the nucleobases, which oen exhibit poor solubility in most conventional solvents.…”