The intramolecular aza-(4 + 3) cycloaddition reactions ofin situgenerated aza-oxyallylic cations and furans have been reported for the construction of medium sized hydroxamate macrocycles.

The main objective of this review is to provide a comprehensive survey of methods used for stereoselective construction of carbon-nitrogen bonds during the total synthesis of nitrogen-containing natural products that have appeared in the literature since 2000. The material is organized by specific reaction in order of decreasing number of applications in natural product synthesis. About 800 total syntheses of natural products with stereogenic carbon-nitrogen bonds described since 2000 have been reviewed.

Facile synthesis of a variety of α-heterosubstituted ketones under mild conditions was achieved by copper-mediated cross-coupling of thioesters with functionalized organostannanes. Application of this coupling methodology provided a concise pathway for the conversion of carboxylic acids to 2-aminoimidazoles, 2-aminothiazoles, and 2-aminooxazoles via thioesters in practical yields.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Michael addition is a premier synthetic method for carbon-carbon and carbon-heteroatom bond formation. Using chiral dilithium amides as traceless auxiliaries, we report the direct enantioselective Michael addition of carboxylic acids. A free carboxyl group in the product provides versatility for further functionalization, and the chiral reagent can be readily recovered by extraction with aqueous acid. The method has been applied in the enantioselective total synthesis of the purported structure of pulveraven B.

Polyheterocyclic scaffolds were prepared by intramolecular aza-[4+3] cycloaddition reactions of aza-oxyallylic cations with cyclic dienes. The aza-oxyallylic cation was generated in situ by the dehydrohalogenation of alpha-halohydroxamates. The highly functionalized heterocyclic products undergo a variety of reactions that provide useful scaffolds for target-directed synthesis, including macrocyclic furans and polyhydroxylated azepanes.

AbstractComputational and experimental data support that the title reaction proceeds through an aza‐oxyallylic cationic intermediate which is stabilized by the N‐alkoxy substituent.

Aza-[4 + 3] cycloadditions of putative aza-oxyallyl cationic intermediates and cyclic dienes are reported. The intermediate is generated by the dehydrohalogenation of α-haloamides. The reaction is general to a variety of α-haloamides and is diastereoselective. Computational and experimental data suggest that an N-alkoxy substituent stabilizes the aza-oxyallyl cationic intermediate.