1392502-49-6Relevant articles and documents
Catalyst-free sp3 C-H acyloxylation: Regioselective synthesis of 1-acyloxy derivatives of the natural product tanshinone IIA
Ding, Chunyong,Li, Jie,Jiao, Mingkun,Zhang, Ao
, p. 2514 - 2520 (2016)
Tanshinone IIA is a valuable bioactive natural product isolated from the well-known Chinese herb Danshen. Structural manipulation of the A-ring of tanshinone IIA is rather limited. In this study, a substrate tautomerization-induced catalyst-free benzylic sp3 C-H acyloxylation approach is reported that allows the direct introduction of various acyloxy groups at the A-ring benzylic methylene of various tanshinone IIA substrates, thus avoiding the use of expensive transition metal catalysts and the production of harmful byproducts. This approach features a unique acid-induced reversible enolization/oxa-conjugate addition process followed by oxidation to exclusively give a series of diverse 1-acyloxylated derivatives under simple conditions in a regioselective manner. Compared with the literature procedures, this protocol demonstrates a higher efficiency, a more robust functional-group tolerance, atom economy, and lower cost.
