Strong Evidence for a Transient Phosphinidenoid Complex

Abstract

Caught in the trap: Two different routes to the thermally unstable phosphinidenoid complex I are described, and chemical evidence for this novel intermediate is provided through selective reactions. For example, methyl iodide, dimethylcyanamide, or butyraldehyde furnished complexes II, III, and IV (see scheme) under very mild conditions.

A Novel N,P,C Cage Complex Formed by Rearrangement of a Tricyclic Phosphirane Complex: On the Importance of Non‐covalent Interactions

“…In contrast, N,P,C cage formation involving transient cycloaddition reactions of 1,3‐dipoles such as nitrilium phosphane ylide complexes16 is rare,17 because the only established route to these transient 1,3‐dipole species relies on reactions of thermally formed electrophilic terminal phosphinidene complexes18 with nitriles at elevated temperatures 19. 20 However, some evidence for a transient 1,3‐dipole was obtained recently, through the formation of P ‐iminoyl phosphane complexes in the reaction of a Li/Cl phosphinidenoid complex and dimethylcyanamide;21 the formation of a C ‐amino‐substituted 2 H ‐azaphosphirene complex pointed in the same direction.…”

Going for strain: synthesis of the first 3-imino-azaphosphiridine complexes and their conversion into oxaphosphirane complex valence isomers

“…Due to our longstanding interest in the chemistry of complexes possessing strained heterocyclic ligands having polar ring bonds such as 2H-azaphosphirenes, 7 oxaphosphiranes 8 and azaphosphiridines, 9 we contemplated about reactions of Li/Cl phosphinidenoid complexes 10 and cumulenes. The first example of this is reported herein, together with theoretical calculations of the ring strain energy of the hitherto unknown complexes VIII and a proposed pathway for their conversion into the first stable valence isomers of oxaphosphirane complexes.…”

First synthesis of chloroformylphosphane complexes

“…The formation and stability of chloroformylphosphane complexes 3a-c was found to be largely dependent on the nature of the substituents at phosphorus, the amounts of phosgene solution employed, and the temperature regime. When phosphinidenoid complex 2a [11] [X = Cl, R = CH(SiMe 3 ) 2 ] was reacted with nearly equimolar amounts of phosgene (20 % solution in toluene) in conditions similar to reported for preparation of analogous organylacylphosphane tungsten(0) complexes [12], no selective formation of the corresponding chloroformylphosphane complex 3a was observed. Instead, rapid formation of dichlorophosphane complex 1a [δ ( 31 P) = 157.6 ppm, 1 J P,W = 330.8 Hz] and some by-products assigned to the chloroformylphosphane complex 3a [δ ( 31 P) = 129.6 ppm, 1 J P,W = 296.3 Hz], chlorophosphane complex 4a [13] [δ ( 31 P) = 53.7 ppm, 1 J P,W = 268.8 Hz, 1 J P,H = 349.4 Hz], and nonidentified species was observed.…”