Transition-metal-mediated reactions of organic isocyanates

Modular N,O‐Chelating Ligands: Group‐4 Amidate Complexes for Catalytic Hydroamination

“…For example, Nb and Ta complexes of the sort M(Me) x Cl y readily insert phenyl or methyl isocyanates, resulting in the methyl group adding to the carbon of the newly formed amidate chelate [Equation (1)]. [51] (1) Analogous reactions occur with [Cp 2 ZrMe 2 ] [52] and Cp 2 TiR [51] complexes and various isocyanates to give complexes of the type 12 ( Figure 6). With respect to polymerization catalysis, complexes like 12 are relevant to more recent examples using TiCl 3 OCH 2 CF 3 and CpTiCl 2 L [L = -OCH 2 CF 3 , -N-(CH 3 ) 2 , -CH 3 ] as catalysts for the living polymerization of isocyanates.…”

Catalytic Degenerate and Nondegenerate Oxygen Atom Transfers Employing N2O and CO2 and a MII/MIV Cycle Mediated by Group 6 MIV Terminal Oxo Complexes

“…[9] Importantly, single-crystal X-ray analyses of 9 and 10 served to establish a k 2 -(O,C) ligation of the tBuNCO group, which, to the best of our knowledge, is the first time that this coordination mode for a metal-complexed isocyanate has been unequivocally established. [20,21] In the solid state, 9 and 10 proved to be nearly isostructural, and accordingly only that of 9 is presented in Figure 2, along with selected geometric parameters. Finally, solid-state infrared spectra (KBr) displayed two sets of strong absorption bands at 2112 (w/sh) cm À1 and 1628 (w/sh) cm À1 for 9, and at 2085, 2054 cm…”

Reactivity of a Dititanium Bis(pentalene) Complex toward Heteroallenes and Main-Group Element–Element Bonds

“…Isocyanates Organic isocyanates, RN=C=O, have also been studied as reagents for modeling the reactivity of CO2, since the introduction of an amido (RN) group results in polarization of the double bonds and thus increased reactivity. 39 Slow addition of PhNCO to a pentane solution of 1 at −35 °C resulted in a green-brown solution upon warming to room temperature, which after concentration and cooling to −35 °C, deposited green single crystals suitable for X-ray diffraction analysis.…”