Convenient synthesis of phosphinecarboxamide and phosphinecarbothioamide by hydrophosphination of isocyanates and isothiocyanates

Abstract

Convenient synthesis of phosphinecarboxamidein by hydrophosphination of isocyanates (and isothiocyanates) was achieved without catalyst and solvent. This system shows shorter reaction time, high yield, and good functional group tolerance.

The first ring-expanded NHC–copper(i) phosphides as catalysts in the highly selective hydrophosphination of isocyanates

“…19 In contrast to the formation of alkyl and alkenyl phosphines from alkenes and alkynes, hydrophosphination of isocyanates has been far less well-studied. Often, significant competing side-reactivity 6 or poor substrate scope 20 hamper access to, and thus exploitation of, phosphinocarboxamide products. These products are potential synthetic intermediates and, particularly, ligands owing to their polydentate nature comprising both hard and soft donor atoms.…”

“…Whilst catalyst-free hydrophosphination of isocyanates can be conducted under strictly neat conditions, the reactivity was limited to a range of small aromatic isocyanates; 20 isocyanate exhibited no reactivity under such conditions. In contrast, 1 mol% of complexes 3 and 4 brought about full conversion of both cyclohexyl and isopropyl isocyanate within 30 minutes, and even the very sterically-congested tert-butyl isocyanate reached excellent conversions (490%) within 2 hours.…”

Reported Catalytic Hydrofunctionalizations that Proceed in the Absence of Catalysts: The Importance of Control Experiments

“…Among heterocumulenes, hydrofunctionalization of isocyanates have been well‐explored and reported in literature. Hydrophosphination reaction of isocyanate was established under neat condition without using catalyst or additive (Table 9, entry1) [57c] . However, earlier, reports on the same conversion using metal catalyst like [Zr] catalyst, [57k] α‐La(dmba) 3 , [57b] actinide complex [57a] were documented (entry 2–4).…”

An efficient catalytic method for hydrophosphination of heterocumulenes with diethylzinc as precatalyst without a solvent

“…Recently, M. Itazaki et al reported the catalyst-free hydrophosphination of isocyanates and isothiocyanates with diphenylphosphine under neat conditions, which limited to a range of small aromatic isocyanates and isothiocyanates. 45 In particular, cyclohexyl isocyanate and adamantylisocyanate exhibited no reactivity under Fig. 1 The structures of aluminum hydride (1) and zinc ethyl (2).…”