Shubhankar Samanta

Novel and rapid palladium-assisted 6pi electrocyclic reaction affording 9,10-dihydrophenanthrene and its analogues.

A novel methodology for the synthesis of 9,10-dihydrophenanthrene and its analogues has been developed via a palladium-assisted 6pi electrocyclic reaction followed by formaldehyde elimination.

One-pot synthesis of highly fluorescent polycyclic benzimidazole derivatives

An efficient one pot synthesis of polycyclic benzimidazole derivatives has been developed (up to 90% yield). The protocol is very mild, metal-free, and not restricted to anhydrous conditions. It also demonstrates an example of preferential electrocyclic reaction over Michael reaction. These new benzimidazole derivatives are highly fluorescent and show a dramatic change with pH; The characteristic bright bluish fluorescence was observed in MeOH (UV-light, 366 nm) but the intensity was totally diminished at pH = 2.5.

Platinum(II)-Catalyzed Novel Synthesis of 3,4-Fused Furans

Abstract A novel synthesis of 3,4-fused furans (both tricyclic and bicyclic) through platinum-catalyzed cyclization of 3-(2-formylcycloalkenyl)-acrylic amides 2 in methanol is described (up to 90% yield). Tricyclic 3,4-fused dihydrofuran derivatives were also obtained via reductive cyclization of 2. The substrates 2 were obtained from β- bromovinyl aldehydes by a Pd-catalyzed Heck reaction. GRAPHICAL ABSTRACT

Pd(0)-catalyzed intramolecular Heck reaction: A general route for fused oxepine derivatives

ABSTRACT A simple and facile approach for the synthesis of various structurally different tricyclic bent oxepine frameworks from a readily accessible precursor has been introduced. The synthesis of substituted oxepine derivative involved Pd(0)-catalyzed Heck reaction. This methodology enriches the literature for the large ring formation. GRAPHICAL ABSTRACT