Modular Synthesis of Heterobenzylic Amines via Carbonyl Azinylative Amination.

Transformations enabling the synthesis of α-alkyl, α'-2-azinyl amines by addition of 2-heteroaryl-based nucleophiles to in situ-generated and non-activated alkyl-substituted iminium ions are extremely rare. Approaches involving classical 2-azinyl organometallics, such as the corresponding Grignard reagents, often fail to produce the desired products. Here, we report an operationally straightforward solution to this problem through the development of a multicomponent coupling process wherein a soft 2-azinyl indium nucleophile, generated in situ from the corresponding 2-iodo heteroarene and indium powder, adds to an iminium ion that is also formed directly in the reaction.

Total Synthesis of (+)-Trachyspic Acid 19-Butyl Ester.

The first total synthesis of the alkyl citrate trachyspic acid 19--butyl ester () is described. A formal [2 + 2]-cycloaddition of the silylketene acetal derived from lactone with di-butylacetylene dicarboxylate provided the cyclobutene diester with a dr >20:1. Acid-mediated rearrangement of followed by lactone ring-opening and ester protecting group manipulation eventually provided orthogonally protected aldehyde .