Insertion von Nitrilen in die P-C-Bindung von [(η1-C5Me5)P{W(CO)5}2] - ein neuer Zugang zu Phosphorheterocyclen

Abstract

Ganz unerwartet inserieren Nitrile bereits bei Raumtemperatur in die ungespannte P‐C‐σ‐Bindung von [Cp*P{W(CO)5}2]. Dabei entstehen je nach verwendetem Nitril Dihydro‐1,3,2‐diazaphosphinin‐ und Benzo‐1,2‐azaphosphol‐Derivate, die durch [W(CO)5]‐Einheiten stabilisiert werden (siehe Schema). Die Synthese des Azaphosphols wird von einer C‐H‐Bindungsaktivierung bei Raumtemperatur begleitet und stellt einen neuen und einfachen Zugang zu dieser Verbindungsklasse dar.

Reactivity of Bridged Pentelidene Complexes with Isonitriles: A New Way to Pentel‐Containing Heterocycles

“…The coordination geometry of the pentel atom changed from trigonal‐planar at the pentelidene in complexes 1 a / b to a slightly distorted tetragonal coordination. With the change of the coordination geometry also an elongation of the EW bonds occurs 11. The newly formed PC and AsC bonds are 1.796(6) and 1.960(6) Å and hence in the normal range of single bonds.…”

“…Photolysis of the pentelidene complexes induces a Cp* radical elimination resulting in the presence of diphosphenes to triphospha‐ or arsadiphosphaallyl radicals 10. Notable in the reaction with nitriles, Cp* migration of the phosphinidene complex occurs yielding new P‐containing heterocycles 11. Interestingly, along with a Cp* ring expansion initiated by MesCP8 (Mes=2,4,6‐Me 3 C 6 H 2 ) and the hydrophosphination reaction to give transient diphospha‐ and arsaphosphanorbornene derivatives,12 for these bridged compounds no formation of heterocycles has been observed so far.…”

Insertion of Thiocyanogen into a PC Bond and Subsequent Formation of Polysulfide Derivatives

“…Noteworthy, the reaction takes place instantaneously at room temperature, although the insertion implies the breaking of a rather strong PC bond 5. Insertion reactions of molecules into PC bonds are very rarely encountered in the literature; examples are the insertion of nitriles either into the PC bond of a phosphinidene complex,6 or into a PC bond of strained three‐membered rings of 2H‐azaphosphirene complexes,7 and the insertion of electron‐poor alkynes into a PC bond of a coordinated phosphane ligand 8…”

Intramolecular [3+2] Cycloaddition of a Nitrilium Phosphane Ylide Complex to theP-Phenyl Group of a Wittig Ylide

“…The results presented here are also interesting in view of recently reported first examples of reactions of other benzene derivatives with μ 1 ‐ and μ 2 ‐phosphanediyl complexes. In the first case a [5]metacyclophane15 reacted as a 4π‐cycloaddition component,16 whereas the second example involved the phenyl group of benzonitrile in a complicated reaction sequence of C−H activation and cyclization17—the aromatic 6π‐electron system, however, remained intact.…”