White AR, Kozlowski RA, Tsai SC, Vanderwal CD. A Direct Synthesis of Highly Substituted π-Rich Aromatic Heterocycles from Oxetanes.
Angew Chem Int Ed Engl 2017;
56:10525-10529. [PMID:
28662280 DOI:
10.1002/anie.201704119]
[Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Indexed: 01/20/2023]
Abstract
The ubiquitous use of π-rich five-membered heterocycles has driven the development of new methods for their synthesis for more than a century. Here, we disclose a general and reliable reaction manifold for the construction of highly substituted heterocycles through a facile Lewis-acid-catalyzed oxetane rearrangement. Notably, this methodology employs a keto-oxetane motif as a 1,4-dicarbonyl surrogate, which can be synthesized using robust alkylation or alkenylation reactions, and thus obviates the need to access 1,4-dicarbonyl compounds via umpoled starting materials. We harnessed this reactivity to generate a broad range of substituted furans and pyrroles, and extended this methodology to produce benzo-fused versions thereof.
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