Half-sandwich rare-earth metal tris(alkyl) ate complexes catalyzed phosphaguanylation reaction of phosphines with carbodiimides: an efficient synthesis of phosphaguanidines

Abstract

The phosphaguanylation reaction of phosphines with carbodiimides catalyzed by half-sandwich yttrium tris(trimethylsilylmethyl) ate complexes is achieved for the first time to efficiently prepare phosphaguanidines.The catalyst system of the yttrium ate complex displays better catalytic activity than those of neutral yttrium complexes.

Broken Promises? On the Continued Challenges Faced in Catalytic Hydrophosphination

“…The products offer novel ligand scaffolds that could be employed in catalysis. 102 , 103 Examples include HP of carbodiimides (RN=C=NR′) and isocyanates (RN=C=O), and these transformations have been dominated by main group-, 104 , 105 lanthanide-, 106 − 109 and actinide-based 110 , 111 catalysis, with some p-block catalysis 112 − 114 being reported in the past decade ( Scheme 12 ).…”

“…Heteroallenes as substrates have been far less explored in HP reactions due to the propensity for unwanted side reactivity such as cyclotrimerization and selectivity issues with either single or double insertion. The products offer novel ligand scaffolds that could be employed in catalysis. , Examples include HP of carbodiimides (RNCNR′) and isocyanates (RNCO), and these transformations have been dominated by main group-, , lanthanide-, − and actinide-based , catalysis, with some p-block catalysis − being reported in the past decade (Scheme ).…”

Catalyst-free Hydrophosphinylation of Isocyanates and Isothiocyanates under Low-Added-Solvent Conditions

“…While alkene and alkyne substrates have been thoroughly explored, − heterocumulenes are comparatively underutilized. There are several reports of catalytic hydrophosphination with heterocumulenes, − and one catalyst-free example . Hydrophosphinylation of heterocumulenes is significantly rarer, with very few literature examples. − This is despite hydrophosphinylation providing an atom economical route to air-stable phosphorus derivates of guanidines, ureas, and thioureas, which have potential applications as ligands, − in the purification of lanthanide containing waste, − in medicine, , and as organic synthons …”

Formation and Reactivity with tBuCN of a Thorium Phosphinidiide through a Combined Experimental and Computational Analysis

“…For example, in our work on the reactivity of actinide phosphido complexes, P–H bond activations via σ-bond metathesis are observed, − but other mechanisms by which P–H activations occur are less straightforward. − Generally, most of these metal-mediated activations involve mononuclear metal complexes, while multimetallic or cooperative examples are limited. , Acquiring further mechanistic insight into these bond activations is important to afford strategies for the functionalization of phosphines, , which are of interest for a wide array of applications. The reactivities of metal alkyl , and hydride − complexes, especially with electropositive metals, help to facilitate these bond activations, and thus a number of examples of P–H bond activation are known with f elements, nearly all involving lanthanide complexes. ,,− …”