We have exploited the Sonogashira coupling of lactam-derived enol phosphates in order to access a class of N-Boc protected enynes. These, in the presence of a gold(I) catalyst, rearranged to give cyclic carbamates which upon treatment with a base provided heterocyclic vinylogous amides. These are important in natural product synthesis and we have exploited one of them for the first total synthesis of alkaloids isolated from a chinese mangrove and Sedum sp. plants (J. Org. Chem. 2013, 78, 1107 and Eur. J. Org. Chem. 2015, 3251).

 

We are currently exploiting the gold(I)-catalyzed sequential [3,3]-rearrangement/Nazarov reaction of suitably functionalized propargylic ester derivatives for the synthesis of annulated N-heterocycles which are useful intermediates in natural product synthesis. See Eur. J. Org. Chem. 2015, 3943 and Org. Lett. 2016, 18, 3922). The bruceolline H has been synthesized by this approach (see Org. Lett 2016 above) as well as the bruceolline I (J. Nat. Prod. 2017, 80, 2384).