1632445-77-2Relevant academic research and scientific papers
Asymmetric synthesis of tetrahydroquinolines through a [3+2] cycloaddition controlled by dienamine catalysis
Li, Wenjun,Wei, Jia,Jia, Qianfa,Du, Zhiyun,Zhang, Kun,Wang, Jian
supporting information, p. 6592 - 6596 (2014/06/09)
A dienamine-mediated enantioselective 1,3-dipolar cycloaddition catalyzed by a chiral prolinol silyl ether catalyst has been developed. Removal of the benzamide group of the intermediates could furnish chiral C-1 substituted tetrahydroisoquinolines (see scheme) in high yields and excellent stereoselectivities.
Control of the dual reactivity (iminium-dienamine) of β-arylmethyl α,β-unsaturated aldehydes in organocatalytic 1,3-dipolar cycloadditions with N-benzoyl C,N-cyclic azomethine imines
Izquierdo, Cristina,Esteban, Francisco,Parra, Alejandro,Alfaro, Ricardo,Alemn, Jos,Fraile, Alberto,Ruano, Jos Luis Garca
, p. 10417 - 10433 (2015/02/19)
1,3-Dipolar cycloadditions of C,N-cyclic azomethine imines with α,β-unsaturated aldehydes can be performed with complete control of the regio-, exo-, and enantioselectivity under aminocatalytic conditions. The so far never studied competence of the iminium-dienamine reactivity inherent to β-alkyl α,β-unsaturated aldehydes was studied, which was possible by allowing achievement of complete control of the chemoselectivity in reactions of the β-arylmethyl derivatives with azomethine imines by using different additives and organocatalysts, whose role has been rationalized by DFT calculations and chemical proofs. Thus, it has been possible to selectively obtain the pyrazolidines resulting from both the attack to the C2-C3 (via iminium) and the C3-C4 (via dienamine) bonds at the starting enals, which can be used as precursors of interesting tetrahydroisoquinolinic compounds.
