Modular synthesis of pentacyclic-fused pyranoquinoliziniums as organelle-selective fluorescent probes.

On basis of their unique chemical and photophysical properties, and excellent biological activities, quinoliziniums have been widely used in various research fields. Herein, modular synthetic strategies for efficient synthesis of novel fluorescent quinoliziniums by using one-pot and stepwise rhodium(III)-catalyzed C-H annulations were developed. In the one-pot synthesis, the reaction between 2-aryl-4-quinolones (1) and 1,2-diarylalkynes (2) proceeded in a chemo- and regioselective manner to give quinolinone-fused isoquinolines (3) and pentacyclic-fused pyranoquinoliziniums (4).

N,N'-(Ethane-1,2-di-yl)bis-(methane-sulfon-amide).

The mol-ecular structure of the title compound, C4H12N2O4S2, has crystallographic inversion symmetry. The central N-C-C-N moiety was refined as disordered over two sets of sites with an approximate occupancy ratio of 3:1 [0.742 (15):0.