Chiral Chelating Systems: Unusual Formation and X-Ray-Structure of Rac-3a(r),4(s),5,9b(s)-Tetrahydro-4-(Pyrid-2-Yl)-3h-Cyclopenta[c]quinoline

Abstract

N-Phenyl-2-(pyrid-2-yl)imine reacts with zinc iodide to give the corresponding diiodo zinc imine complex 1. I reacts with cyclopentadiene (CPD) at 0°C under ultrasound-assisted conditions to yield rac3a(R),4(S),5,9b(S)-tetrahydro-4-(pyrid-2-yl)-3//-cyclopenta[c]quino-line 2 instead of N-phenyl-5-aza-6-pyrid-2-ylnorborn-2-ene. The starting imine reacts with CPD in the same way yet more smoothly using BF, Et,0. With both Lewis-acids, the reaction proceeds regio-and distereoselectively. 1 crystallizes in the centrosymmetric space group Pi, a = 8.127 (1), b = 9.133(1), c = 10.467(1) A,"a = 104.36(1)°, β = 100.35(1)°, γ= 95.93(1)°V = 731.4(1) Ä\ Ζ = 2. 2 crystallizes in the centrosymmetric space group P2,/c. a = 10.559(3)), b = 15.061(2), c = 8.252(1) Α, β = 95.90(2)°, V = 13054(4) A 3 , Ζ = 4.

Insight into inhibition of the human amyloid beta protein precursor (APP: PDB ID 3UMI) using (E)-N-(pyridin-2-ylmethylene)arylamine (LR) models: structure elucidation of a family of ZnX2-LRcomplexes

“…On the other hand, a wide variety of Zn(II) complexes containing (E)-N-(pyridin-2-ylmethylene)arylamine (L R ) have been synthesized and their structures have been determined, for example [Zn(I) 2 (L H )], 16 [Zn(Br) 2 (L 4-I )], 17 [Zn(Cl) 2 (L 4-I )], 18 [Zn(I) 2 (L 4-Br )], 19 [Zn(I) 2 (L 2,5-Me2 )], 20 [Zn(Cl) 2 (L H )], 21,22 [Zn(Cl) 2 -(L 4-NMe2 )], 22 [Zn(Br) 2 (L 4-NO2 )], 23 [Zn(I) 2 (L 4-OMe )], 24 [Zn(Br) 2 -(L 4-F )], 25 [Zn(Br) 2 (L H )], 26 [Zn(Cl) 2 (L 2-Me )], 26 [Zn(Cl) 2 (L 4-Me )], 26 [Zn(Cl) 2 (L 4-CO2Me )], 26 [Zn(Br) 2 (L 4-CO2Me )], 26 [Zn(I) 2 (L 4-CO2Me )], 26 [Zn(Cl) 2 (L 2-OMe )] 26 and [Zn(μ-N 3 )(N 3 )(L 4-Me )] 2 . 26 In all the complexes, the zinc centre displays a moderately distorted tetrahedral coordination geometry defined by two halide anions and two N atoms of the ligand L R , except for the last two complexes.…”