Nucleophilic Ring Opening of Donor–Acceptor Cyclopropanes with the Cyanate Ion: Access to Spiro[pyrrolidone-3,3′-oxindoles]

The nucleophilic ring opening of donor–acceptor cyclopropanes with the cyanate ion is reported for the first time. Cyclopropanes, spiro-activated with oxindole fragments as acceptors, are shown to undergo transformations into biologically relevant spiro­[pyrrolidone-3,3′-oxindoles] while being treated with potassium cyanate under microwave assistance

Regioselective Hydrogenolysis of Donor–Acceptor Cyclopropanes with Zn-AcOH Reductive System

A convenient low-cost method for regioselective ring-opening of donor–acceptor cyclopropanes with the Zn-AcOH reductive system was developed. The general character of the method was displayed via efficient reduction of a representative series of 2-(het)­arylcyclopropane-1,1-diesters as well as donor–acceptor cyclopropanes with other types of electron-withdrawing activating groups. This method opens a rapid access to γ-substituted propyl-1,1-diesters, ketoesters, cyanoesters, cyanoamides, dinitriles, etc., many of which are not readily accessible with alternative methods. The utility of the synthesized compounds was demonstrated by transforming them into valuable acyclic and cyclic compounds (including pharmacologically relevant carbazoles, δ-lactams, and oxindole derivatives)

l‑Alanine/Nickel-Induced Size Sorting of Lanthanide(III) Ions in 4f–4f′ Heterometallic Complexes

A versatile approach to create a novel class of mixed-lanthanide compounds with predetermined locations of different lanthanides in cationic and anionic positions has been developed. Pure 4f–4f′ heterometallic complexes were constructed from two independent building blocks: the complex cation [Ln­{Ni­(ala)₂}₆]³⁺ (ala = l-alaninate), which can be formed by La³⁺, Ce³⁺, Pr³⁺, and Nd³⁺ exclusively, and the anion [Gd­(NO₃)₃(OH)₃(H₂O)]^3–. The compositions and structures of the complexes were studied by X-ray crystallography, energy-dispersive X-ray spectroscopy, and inductively coupled plasma mass spectrometry. The X-ray structural analysis showed the high rigidity of the l-alanine/Ni­(II) supramolecular unit in the complex cations, which affected immediately its selectivity toward certain lanthanides