Photoinitiated chain decomposition of phenyl isocyanate via its reaction with phenylnitrene

Total Synthesis of (±)-Kainic Acid: A Photochemical C–H Carbamoylation Approach

“…As far as we know, this is the first example of the intermolecular addition of a photochemically generated α-amino alkyl radical to phenyl isocyanate to furnish amino acid anilides. It has been reported that PhNCO is decomposed by UV irradiation (227 nm) to give phenylnitrene . However, in the present case, most of the unreacted PhCNO could be recovered as methyl phenylcarbamate after quenching the reaction mixture with MeOH.…”

“…It has been reported that PhNCO is decomposed by UV irradiation (227 nm) to give phenylnitrene. 13 However, in the present case, most of the unreacted PhCNO could be recovered as methyl phenylcarbamate after quenching the reaction mixture with MeOH. The successful recovery of the unreacted isocyanate is probably attributable to circumvention Scheme 1.…”

“…It has been reported that PhNCO is decomposed by UV irradiation (227 nm) to give phenylnitrene. 13 However, in the present case, most of the unreacted PhCNO could be recovered as methyl phenylcarbamate after quenching the reaction mixture with MeOH. The successful recovery of the unreacted isocyanate is probably attributable to circumvention of its decomposition by using a Pyrex reaction vessel that filters short-wavelength light (<300 nm) as well as by the appropriate spectral energy distribution of a high-pressure Hg lamp that has no spectral distribution around 230 nm.…”

Phosphenic isocyanate (O2PNCO): gas-phase generation, characterization, and photodecomposition reactions

“…It is known that nitrenes can be generated through photolytic CO-elimination from the NCO group in covalent isocyanates. 30 In sharp contrast to the thermal decomposition, photolysis of a at 193 nm causes CO-elimination by yielding a novel phosphinonitrene C 2 H 4 O 2 PN (n, Fig. S6 and S7, ESI †).…”

“…It is known that nitrenes can be generated through photolytic CO-elimination from the NCO group in covalent isocyanates. 30 By analogy, the nitrene intermediate O 2 PN ( p , Scheme 2) should be involved in the decomposition of O 2 PNCO. To aid the identification, calculations on the IR spectrum of O 2 PN were performed (Table S2, ESI†).…”