Carbodiphosphorane: die Chemie von zweibindigem Kohlenstoff(0)

Abstract

Eine theoretisch/experimentelle Untersuchung liefert Hinweise, dass Carbodiphosphorane als Verbindungen mit zweibindigem Kohlenstoff(0)‐Atom einzuordnen sind. Carbodiphosphorane haben zwei freie Elektronenpaare (siehe Schema), die den Molekülen ungewöhnliche Eigenschaften verleihen. Die Synthese eines dreifach geladenen Moleküls, bei dem zwei protonierte Carbodiphosphorane als Elektronendonoren für Ag+ wirken, stützt dieses Bindungsmodell.

Do Extremely Bent Allenes Exist?

“…[16,18] These results can be contrasted to data reported for carbodiphosphoranes 7 which, even as isolated molecules, appear as true divalent carbon(0) compounds. [19,23,24] A comparison of 1a to data reported for imidazol-2-ylidene [16,25] and carbodicarbenes [16] reveals that, as an isolated entity, its electronic structure has more in common with the former. Hence, it can be expected that systems 1 function as two electron donors unless extremely strong electrophiles are used.…”

Recent Advances in the Field of Main‐Group Mono‐ and Diatomic “Allotropes” Stabilised by Neutral Ligands

“…The bonding arrangements in most examples reported to this date are L-E-L or L-E-E-L, in which E is the main group element of interest, and L is a neutral ligand. The field started in the 2005-2006 with the "rediscovery" of the carbodiphosphorane (1), [1] suggesting a "dative model" 1 b to be more accurate than the traditional depiction as 1 a, and Robinsons report of an N-heterocyclic carbene (NHC) stabilised disilene (3 Si), [2] described by Bertrand as a soluble "allotrope" of Si. [3] Since these two reports, a number of leading main-group chemists have been working in the area, including the groups of Bertrand, Braunschweig, Driess, Roesky, Robinson, Schmidbaur and Jones (synthetic), and Frenking, Schaefer and Schleyer (theory).…”

Synthesis of a Mixed Phosphonium–Sulfonium Bisylide R3PCSR2

“…[12] The preparation of such derivatives should be of major significance because of the synthetic impact of both types of ylides (P and S). Experimental Section 2: A solution of nBuLi (1.6 m in hexanes, 2.0 mmol) was added dropwise to a solution of diphenylmethylsulfonium triflate (0.70 g, 2.0 mmol) in THF (10 mL) at À78 8C.…”