A New Monomeric Saturated N-Heterocyclic Silylene as a Racemic Mixture

Abstract

A new stable silylene, rac-N,N‘-di-tert-butylethylene-4,5-dimethyl-1,3-diaza-2-silacyclopentan-2-ylide, has been made by reaction of the corresponding dibromide with KC8. Unlike the analogous silylene lacking the two methyl groups, which tetramerizes in concentrated solution or as a solid, the new silylene shows no tendency to oligomerize; instead, it persists as a stable colorless liquid.

Synthesis and reactivity of N-aryl substituted N-heterocyclic silylenes

“…Silylene 9b (1 g, 3.42 mmol) was dissolved in thf (50 mL) and added to the solution of W(CO) 5 (thf) 30. The mixture was stirred over night at room temperature.…”

“…Stable silylenes 1-8 [1][2][3][4][5][6][7][8][9][10][11] are known for several years and most of the well-characterized examples are N-heterocyclic silylenes (NHSi), in which the di-coordinated silicon atom is substituted by two nitrogen atoms. Although the synthesis of NHSis 1 [1], 2a [2], 3a [4] were reported already 15 years ago, the chemistry of these compounds and their use in synthesis is still very limited, in particular when compared with the analogous N-heterocyclic carbenes.…”

Synthesis and characterization of three new thermally stable N-heterocyclic germylenes

“…Herein we report the synthesis and characterization of rare examples of saturated N-heterocyclic germylenes derived from simple diamines: compound 1 (as a racemic mixture), the germanium analogue of the previously reported racemic N-heterocyclic silylene Me 2 [NN]Si, [19] and compounds 2 and 3, the latter also a racemic mixture. The structures of 1, 2, and 3 are similar to that of E but with substitution of alkyl groups at the backbone carbon atoms.…”

Chemische Tricks zur Zähmung von Silanonen und ihren schweren Homologen mit EO‐Bindungen (E=Si–Pb): von schwer fassbaren Spezies zu isolierbaren Bausteinen

“…Beispielsweise ergibt die Reaktion des Silylens 1 mit Sauerstoff bei À78 8C das Dimerpaar 2 a und 2 b (Schema 2). [22] Auf ähnliche Weise wurde das Dimer 4 aus der Reaktion des Silylens 3 mit TEMPO erhalten. [23] Silylen 5 liefert dagegen mit TEMPO ein isolierbares Siloxysilan 6.…”