Categories: Synthesis of N-Heterocycles >
Synthesis of 1,2,3,6-tetrahydropyridines
A palladium-catalyzed highly 6-endo-selective alkyl-Heck reaction of unactivated alkyl iodides provides efficient access to various 5-phenyl-1,2,3,6-tetrahydropyridine derivatives, which are important structural motifs for bioactive molecules. Mechanistic investigations reveal a hybrid palladium-radical process.
X. Dong, Y. Han, F. Yan, Q. Liu, P. Wang, K. Chen, Y. Li, Z. Zhao, Y. Dong, H. Liu, Org. Lett., 2016, 18, 3758-3761.
The ion-paired Lewis acid [FeCl2]+[FeCl4]- generated by the in situ disproportionation of FeCl3 catalyzes an aza-Diels-Alder reaction of nonactivated dienes and imines.
R. Tomifuji, J. Maeda, T. Takahashi, T. Kurahashi, S. Matsubara, Org. Lett., 2018, 20, 7474-7477.
[Et3NH]+[BF4]- as an H-bond donor in a toluene/water/(CH2OH)2 biphasic system efficiently promotes a transition-metal catalyzed carbon-halogen reductive elimination at low temperature. This enables a series of Pd(0)-catalyzed carbohalogenation reactions, including an unprecedented asymmetric carbobromination in the presence of readily available ligands.
X. Chen, J. Zhao, M. Dong, N. Yang, J. Wang, Y. Zhang, K. Liu, X. Tong, J. Am. Chem. Soc., 2021, 143, 1924-1931.