C-element-substituted phosphorus ylids

An Isolable Mixed P,S‐Bis(ylide) as an Asymmetric Carbon Atom Source

“…[5,6] Surprisingly, their chemical properties as an atomic carbon source have received very little attention, with the exception of carbodiphosphoranes (CDPs) IIIa. [7] CDPs are known to react with two equivalents of ketone, leading to the formation of cumulenes as a result of a double-Wittig reaction. We have recently described the synthesis of the first persistent mixed P,S-bis(ylide) of type IIIb.…”

“…As a consequence, the P À C bond is strengthened, and the P À O bond is weakened, which could explain the increased reluctance of 4 to undergo a Wittig-type reaction as for 7. [7] Taking into account the electronic features of 4 a, we considered the use of a Lewis acid catalyst to accelerate the Wittig reaction. Indeed, the formation of adduct 8 by …”

1,1,3,3,3-Pentafluoro-2-pentafluorophenylpropene oxide. Precursor for novel phosphonates and ylides

“…The NMR data of the ylide [1,4,9] and the phosphonates [1,2] [7] were prepared according to literature procedures. …”

Dative Bindungen bei Hauptgruppenelementverbindungen: ein Plädoyer für mehr Pfeile

“…Erst 1978 ergab eine Rçntgenstrukturanalyse eine gewinkelte Struktur mit einem Bindungswinkel von 131.78. [27] An der Schreibweise mit mesomeren Grenzformeln hat dies zunächst nichts geändert, [28] bis wir 2006 zeigten, [2] Bindungsdissoziationsenergien D e der Liganden NHC oder cAAC. [33] .…”