1,3‐Bis(triphenylphosphoranyliden)allen und Tribenzyl(4‐methyldiphenylphosphoniobutadiinyl)‐borat, stabilisiertes C₃ und C₄ ‐die Bestätigung einer Hypothese

Abstract

„Nackte”︁ C3‐ und C4‐Einheiten werden, wie vorausgesagt, durch zwei Triphenylphosphanmoleküle als Donoren bzw. einen Methyldiphenylphosphan‐Donor und einen Tribenzylboran‐Acceptor an den Enden der Cx‐Kette stabilisiert und konnten in Form von 1 bzw. 2 synthetisiert werden.

Lewis Base Stabilized Dicarbon: Predictions from Theory

“…10 In each case, both lone pairs of electrons on carbon were predicted and confirmed to be chemically accessible 11–13. Phosphine‐stabilized “C 3 ” has also been reported, but not structurally verified 14…”

BiotecVisions 2014, February

“…20, 24 This study was preceded by work of Bestmann et al 138. who prepared and formulated Ph 3 PCCBPh 3 as a push–pull adduct of C 2 : (Ph 3 P→CC→BPh 3 ), along with the corresponding butadiyne system R 3 P‐CCCC‐BR 3 139. A very recent theoretical study of a model compound (Me 3 P)CC(PMe 3 ) gave a Z‐type structure with C i symmetry, a CC bond length of 1.349 Å and C‐C‐P angles of 116.2° 140a.…”

“…The compound was finally prepared in 1993 from a racemic allene precursor by treatment with a base and obtained as an orange solid of m.p. 73 °C 139. A structure with a linear C 3 unit and two C‐C‐P angles as shown in formula 41 was proposed ( C 2 symmetry).…”