Keiichiro Tateishi, Keiichi Noguchi and Akio Saito
Org. Biomol. Chem., 2018,16, 5965-5968
DOI:
10.1039/C8OB01774C,
Communication
2-Picoline efficiently catalyzes the formation of α,β-enones from acetylenedicarboxylates and aldehydes in the presence of alkenes, thereby leading to pyrans in moderate to good yields with complete regioselectivities. This synthetic method of pyrans is represented as a first example of catalytic and direct [2 + 2 + 2] cycloaddition of three different components under the metal-free conditions.
![Graphical abstract: 2-Picoline catalyst-triggered [2 + 2 + 2] cycloaddition-type reaction of acetylenedicarboxylates, aldehydes and alkenes](/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=C8OB01774C "Graphical abstract")
