Novel synthetic method for N-allylcarbamates from allyl ethers using chlorosulfonyl isocyanate

Various allyl ethers were converted into the corresponding N-allylcarbamates using chlorosulfonyl isocyanate (CSI) via the stable allylic carbocation rather than β-lactam through [2+2] cycloaddition. The reaction of cinnamyl methyl ether with CSI afforded only methyl N-cinnamylcarbamate at 0°C, but at 20°C, it produced a mixture of methyl N-cinnamylcarbamate and methyl N-(1-phenylprop-2-enyl)carbamate in a 2.7:1 ratio.