Gold(I)-Catalyzed Intramolecular Hydrothiophenylation of N -Thiophen-3-yl Alkynylamides for Accessing Thieno[3,2- b ]pyridine-5(4 H )-ones: Development of F-Actin Specific Fluorescent Probes.

Herein, we describe an original synthetic method for a series of fluorescent thieno[3,2- b ]pyridine-5(4 H )-one derivatives prepared via the gold(I)-catalyzed 6- endo -dig intramolecular hydrothiophenylation process involving N -thiophen-3-yl alkynylamides. The brightness was improved; emission could be tuned, and larger Stokes shifts were recorded. We also designed and synthesized the phalloidin-based fluorescent chemical probes KF - P1 and KF - P2 to realize fluorescent F-actin imaging.