An Efficient One-Pot Green Approach for the Synthesis of Α-aminonitriles with Alsba-15 as Nano Tubular Catalytic Reactor

Abstract

Nanoporous heterogeneous AlSBA-15 (<em>x</em>) type aluminosilicate catalyst with different <em>n</em>_Si/<em>n</em>_Alratios (<em>x</em> = 41, 129, and 210) was synthesized using hydrothermal method. AlSBA-15 catalysts were characterized by XRD, N₂sorption, TPD-NH₃, FT-IR, SEM and TEM. XRD analyses of AlSBA-15 catalysts confirmed the presence of well-ordered crystalline structure with <em>p</em>6<em>mm</em> symmetry. N₂ isotherm of AlSBA-15 catalyst materials showed a type IV adsorption isotherm with H1 hysteresis loops. The specific surface area and specific pore volume of the AlSBA-15 catalysts are in the rage from 480 to 757 m²/g and from 0.65 to 0.95 cm³/g, respectively. SEM analysis of AlSBA-15 (41) revealed a worm-like particle morphology comprising particles in a size range of 3 μm with the co-existence of smaller particles of <em>ca.</em> 1 μm size. A distinct approach adopted for the synthesis of α-aminonitriles using heterogeneous nanoporous AlSBA-15 catalyst via Strecker reaction. This one-pot, three component system of amines (primary/secondary), carbonyl compounds (aldehydes/ketone) and TMSCN compounds proceed excellently in the presence of AlSBA-15 catalyst in water medium at room temperature (RT). The major advantages are excellent yield, short reaction time, high chemo-selectivity, simple experimental procedure, recyclability of the catalyst, easy work up procedure. This one-pot synthesis consists of two consecutive steps: (1) imine formation from amine and aldehyde/ketone and (2) cyano addition to imine. The findings suggest that catalyst is recyclable and can be reused up to six cycles.