A theoretical investigation on the mechanism of a palladium-mediated formal 6pi electrocyclic synthesis of 9,10-dihydrophenanthrenes.
Recently, a new method for the palladium-catalyzed synthesis of 9,10-dihydrophenanthrenes was published. A proposed mechanism indicated that the reaction proceeds via a disrotatory 6pi electrocyclic ring closing reaction. Although the synthetic methodology is excellent for the preparation of 9,10-phenanthrenes, we propose an alternative mechanism that occurs through an intramolecular Heck reaction. Using theoretical calculations, we have investigated both mechanisms and find that the intramolecular Heck mechanism is lower in energy by 21.3 kcal/mol than the electrocyclic pathway.
Lan
Yu
Y
Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China.
Wang
Can
C
Sowa
John R
JR
Wu
Yun-Dong
YD