The synthesis and functionalization of amines are fundamentally important in a vast range of chemical contexts. We present an amine synthesis that repurposes two simple feedstock building blocks: olefins and nitro(hetero)arenes. Using readily available reactants in an operationally simple procedure, the protocol smoothly yields secondary amines in a formal olefin hydroamination. Because of the presumed radical nature of the process, hindered amines can easily be accessed in a highly chemoselective transformation. A screen of more than 100 substrate combinations showcases tolerance of numerous unprotected functional groups such as alcohols, amines, and even boronic acids. This process is orthogonal to other aryl amine syntheses, such as the Buchwald-Hartwig, Ullmann, and classical amine-carbonyl reductive aminations, as it tolerates aryl halides and carbonyl compounds.

[reaction: see text] 1,3-Diketones were synthesized directly from ketones and acid chlorides and were then converted in situ into pyrazoles by the addition of hydrazine. This method is extremely fast, general, and chemoselective, allowing for the synthesis of previously inaccessible pyrazoles and synthetically demanding pyrazole-containing fused rings.

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o-Halosubstituted aromatic triazenes (e.g. I, Scheme 1) react with aryloxides (e.g. II, Scheme 1) in the presence of CuBr´Me 2 S, K 2 CO 3 and pyridine in acetonitrile at reflux to afford biaryl ethers (e.g. V, Scheme 1). This general methodology (Tables 1 and 2) was applied to the construction of the C-O-D and D-O-E vancomycin model systems 37 (Scheme 2) and 50 (Scheme 3), demonstrating its potential in a projected total synthesis of vancomycin (1, Figure 1). For the construction of the vancomycin model AB biaryl ring system, a sequential strategy involving a Suzuki coupling of the C-O-D aryl iodide 74 (Scheme 7) and boronic acid 53 (Scheme 4), followed by macrolactamization was demonstrated, in which the preformed C-O-D ring framework served to preorganize the precursor for cyclization. The latter investigation led to Suzuki-coupling-based asymmetric synthesis of biaryl systems in which 2,2-bis(diphenylphosphino)-1,1'-binaphthyl (BINAP) was found to be the optimum ligand (Tables 3 and 4).