Nesreen S.I. Ahmed

Bio: Nesreen S.I. Ahmed is an academic researcher. The author has contributed to research in topics: One-pot synthesis & Quinoline. The author has an hindex of 1, co-authored 2 publications receiving 7 citations.

1,3-Difunctionalization of alkenes: state-of-the-art and future challenges

Abstract: The direct difunctionalization of alkenes has emerged as a sustainable and versatile strategy for the efficient construction of complex molecules from simple chemical feedstocks. Specifically, the 1,3-difunctionalization of alkenes enables the simultaneous installation of functional groups at the non-classical 1,3-position of alkenes. Thus, these chemical transformations create new bond disconnection strategies in chemical synthesis. This emerging strategy has identified a novel pathway for the further development of alkene transformations, and has even been applied to the synthesis of various complex biologically active molecules and pharmaceutical candidates. This review summarizes the advances in the development of 1,3-difunctionalization of alkenes mediated by Pd-, Ni-, Fe-, and Cu-based catalysts, as well as under metal-free conditions, over the past few decades, with an emphasis on the reaction mechanisms and factors governing regioselectivity.

Indium-Organic Framework with soc Topology as a Versatile Catalyst for Highly Efficient One-Pot Strecker Synthesis of α-aminonitriles.

Abstract: An In(III) based metal-organic framework (MOF), In-pbpta, with soc topology was constructed from the trigonal prismatic [In3(μ3-O)(H2O)3(O2C-)6] secondary building unit (SBU) and a custom-designed tetratopic linker H4pbpta (pbpta = 4,4',4″,4‴-(1,4-phenylenbis(pyridine-4,2,6-triyl))-tetrabenzoic acid)). The obtained MOF shows a Brunauer-Emmett-Teller surface area of 1341 m2/g with a pore volume of 0.64 cm3/g, which is the highest among the scarcely reported In-soc-MOFs. The constructed MOF demonstrates excellent performance as a heterogeneous Lewis acid catalyst for highly efficient conversion in a one-pot multicomponent Strecker reaction for the preparation of α-aminonitriles under solvent-free conditions, which can be easy to separate and recycle without significant loss of activity for up to seven cycles. The computational modeling studies suggest the presence of the three substrates in close vicinity to the In-oxo cluster. The strong interactions of the aldehyde/ketone and the amine with the In-oxo cluster together with the readily available cyanide ion around the In-oxo cluster lead to high catalytic conversion within a short period of time for the MOF catalyst. Our work therefore lays a foundation to develop MOF as a new class of efficient heterogeneous catalyst for one-pot Strecker reaction.

Nickel-Catalyzed Synthesis of an Aryl Nitrile via Aryl Exchange between an Aromatic Amide and a Simple Nitrile

Abstract: Herein, a nickel-catalyzed synthesis of an aryl nitrile via aryl exchange between an aromatic amide and a simple nitrile was developed. By using cheap, easy-to-handle, and low-toxic 4-cyanopyridine as the cyanating source, cyanation of various aromatic amides afforded an assortment of aryl nitriles including bioactive drugs and organic luminescent molecules in good yields. The reaction exhibited wide substrate scope, good functional group tolerance, and unique selectivity that were complementary to traditional methods. Moreover, two key nickel complexes formed by oxidative addition to each substrate are obtained and determined by X-ray crystallography, which gave strong support for the mechanism elucidations.