O-propargylic carbamate

Carbamates are also effective nucleophiles for the gold(I)intramolecular hydroamination of alkynes [12]. For example, treatment of O-propargylic carbamate 10 with a catalytic 1 1 mixture of (PPh3)AuCl and AgOTf in dichloromethane at room temperature led to isolation of 2,5-dihydroisoxazole 11 in 88% yield (Eq. (11.8)). The transformation was effective for alkyl-, alkenyl- and aryl-substituted internal alkynes and terminal alkynes and for N-Boc, Cbz, and Ts derivatives. A similar... 

It is worth mentioning the synthesis of cyclic a-methylene carbamates, which were also produced via Markovnikov intramolecular nucleophilic addition of O-car-bamates, generated in situ from a propargylic amine and CO2, in the presence of Ru(cod) (cot)/phosphine as catalyst precursor (cod cyclooctadiene cot cycloocta-triene) (Scheme 8.23) [75]. 

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