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Access to benzo-fused nine-membered heterocyclic alkenes with a trifluoromethyl carbinol moiety via a double decarboxylative formal ring-expansion process under palladium catalysis.

ABSTRACT: Direct access to pharmaceutically attractive benzo-fused nine-membered heterocyclic alkenes 3 with a trifluoromethyl carbinol moiety was achieved via a palladium-catalyzed double-decarboxylative formal ring-expansion process from six-membered trifluoromethyl benzo[d][1,3]oxazinones 1 to nine-membered trifluoromethyl benzo[c][1,5]oxazonines 3 in the presence of vinylethylene carbonates 2. Generation of a Pd-?-allyl zwitterionic intermediate was proposed in the catalytic cycle. The trifluoromethyl group in the benzoxazinanones 1 plays an important role throughout the transformation. Diastereoselective chemical transformations of products 3 were also demonstrated.

SUBMITTER: Das P

PROVIDER: S-EPMC5915791 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature

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Access to benzo-fused nine-membered heterocyclic alkenes with a trifluoromethyl carbinol moiety via a double decarboxylative formal ring-expansion process under palladium catalysis.

Das Pulakesh P Gondo Satoshi S Nagender Punna P Uno Hiroto H Tokunaga Etsuko E Shibata Norio N

Chemical science 20180223 13

Direct access to pharmaceutically attractive benzo-fused nine-membered heterocyclic alkenes 3 with a trifluoromethyl carbinol moiety was achieved via a palladium-catalyzed double-decarboxylative formal ring-expansion process from six-membered trifluoromethyl benzo[d][1,3]oxazinones 1 to nine-membered trifluoromethyl benzo[c][1,5]oxazonines 3 in the presence of vinylethylene carbonates 2. Generation of a Pd-π-allyl zwitterionic intermediate was pro ...[more]

PMID: 29732106

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