Modular and stereoselective synthesis of tetrasubstituted helical alkenes via a palladium-catalyzed domino reaction.
A highly modular and stereoselective synthesis of tetrasubstituted helical alkenes is accomplished by a Pd-catalyzed norbornene-mediated domino reaction. This protocol features the rapid assembly of four C-C bonds via sequential C-H activations and carbopalladations along with efficient access to enantiopure bromoalkyl aryl alkyne precursors using homologative alkynylation as the key transformation. Three distinct elements of stereoselectivity were observed in the preparation of the chiral helical alkenes: retention of stereochemistry of the substrates, induced helical diastereoselectivity in the alkene formation, and the exclusive exo-facial selectivity of the norbornene incorporation.
Davenport Laboratories, Department of Chemistry, University of Toronto , Toronto, Ontario, Canada M5S 3H6.
Hongqiang
H
Liu
Mohamed
M
El-Salfiti
David I
DI
Chai
Jérémy
J
Auffret
Mark
M
Lautens
D000475:Alkenes / Q000138:chemical synthesis* / Q000737:chemistry; D000812:Anhydrides / Q000737:chemistry; D002384:Catalysis; D015394:Molecular Structure; D009636:Norbornanes / Q000737:chemistry; D010165:Palladium / Q000737:chemistry*; D013237:Stereoisomerism
D000475:Alkenes; D000812:Anhydrides; D009636:Norbornanes; C085227:norbornene anhydride; D010165:Palladium