676-59-5Relevant articles and documents
Proton transfer: Vs. oligophosphine formation by P-C/P-H σ-bond metathesis: Decoding the competing Br?nsted and Lewis type reactivities of imidazolio-phosphines
Cica?-Hudi, Mario,Feil, Christoph M.,Birchall, Nicholas,Nieger, Martin,Gudat, Dietrich
supporting information, p. 17401 - 17413 (2020/12/28)
Studies of the protonation and alkylation of imidazolio-phosphides and deprotonation of imidazolio-phosphines reveal a complex behaviour that can be traced back to an interplay of Br?nsted-type proton transfers and Lewis-type P-P bond formation reactions. As a consequence, the expected (de)protonation and (de)alkylation processes compete with reactions producing cyclic or linear oligophosphines. A careful adjustment of the conditions allows us to selectively address each reaction channel and devise specific synthesis methods for primary, secondary and tertiary imidazolio-phosphines, imidazolio-alkylphosphides, and cyclic oligophosphines, respectively. Mechanistic studies reveal that oligophosphines assemble in sequential P-P bond formation steps involving the condensation of cationic imidazolio-phosphines via σ-bond metathesis and concomitant elimination of an imidazolium ion. Imidazolio-phosphides catalyse these transformations. Computational model studies suggest that the metathesis proceeds in two stages via an initial nucleophilic substitution under expulsion of a carbene, and a subsequent proton transfer step that generates an imidazolium cation and provides the driving force for the whole transformation. As energy barriers are predicted to be low or even absent, different elementary steps are presumed to form a network of mutually coupled equilibrium processes. Cyclic oligophosphines or their dismutation products are identified as the thermodynamically favoured final products in the reaction network.
Reducing properties of potassium silyl
Williams, Victor A.,Ritter, David M.
, p. 3278 - 3280 (2008/10/08)
Potassium silyl has been found to act preferentially as a powerful reducing agent rather than as a nucleophilic substitution agent. Reactions with phosphorus trichloride and dimethylchlorophosphine gave polymers containing phosphorus-hydrogen bonds. Trimethylchlorosilane underwent transmetalation with its complicated consequences; carbon dioxide was reduced to carbon monoxide and potassium formate, and nitrous oxide gave nitrogen. Silane and polymeric silicon hydrides were produced in all reactions. Titration of potassium silyl with carbon dioxide showed that the reaction is stepwise and complex.
SYNTHESE UND UMLAGERUNGSREAKTIONEN VON o-FUNKTIONELLEN PHENYLLITHIUM- UND PHENYLNATRIUM DERIVATEN DER IVB UND VB-ELEMENTE
Heinicke, J.,Nietzschmann, E.,Tzschach, A.
, p. 1 - 8 (2007/10/02)
While o-substituted bromobenzene derivatives of the type o-BrC6H4XERn (X = O, S; ERn = SiMe3) and n-BuLi undergo metal halogen exchange followed by silyl-X -> C rearrangement, the corresponding compounds of phosphorus, arsenic or tin are split at the E-X bond. o-Metal derivatives o-MI-C6H4XERn (X = O, NMe; E = P, As, Sn) of these elements may be generated, however, by direct reaction with sodium or lithium.They are unstable and furnish o-hydroxy- and o-aminophenyl element(IV, V) derivatives via an intramolecular anionic rearrangement.
