A Mesoporous Indium Metal–Organic Framework: Remarkable Advances in Catalytic Activity for Strecker Reaction of Ketones

With the aim of developing
new highly porous, heterogeneous Lewis
acid catalysts for multicomponent reactions, a new mesoporous metal–organic
framework, InPF-110 ([In3O­(btb)2­(HCOO)­(L)],
(H3btb = 1,3,5-tris­(4-carboxy­phenyl)­benzene
acid, L = methanol, water, or ethanol), has been prepared with indium
as the metal center. It exhibits a Langmuir surface area of 1470 m2 g–1, and its structure consists of hexagonal
pores with a 2.8 nm aperture, which allows the diffusion of multiple
substrates. This material presents a large density of active metal
sites resulting in outstanding catalytic activity in the formation
of substituted α-aminonitriles through the one-pot Strecker
reaction of ketones. In this respect, InPF-110 stands out compared
to other catalysts for this reaction due to the small catalyst loadings
required, and without the need for heat or solvents. Furthermore,
X-ray single crystal diffraction studies clearly show the framework–substrate
interaction through coordination to the accessible indium sites.