Intermolecular sp3-C-H Amination for the Synthesis of Saturated Azacycles.
Kerry N BetzNicholas D ChiappiniJustin Du BoisPublished in: Organic letters (2019)
The preparation of substituted azetidines and larger ring, nitrogen-containing saturated heterocycles is enabled through efficient and selective intermolecular sp3-C-H amination of alkyl bromide derivatives. A range of substrates are demonstrated to undergo C-H amination and subsequent sulfamate alkylation in good to excellent yield. N-Phenoxysulfonyl-protected products can be unmasked under neutral or mild basic conditions to yield the corresponding cyclic secondary amines. The preparative convenience of this protocol is demonstrated through gram-scale and telescoped multistep procedures. Application of this technology is highlighted in a nine-step total synthesis of an unusual azetidine-containing natural product, penaresidin B.