Search

An expansion of methodologies aimed at the formation of versatile organonitriles, via the intramolecular aminocyanation of unactivated alkenes, is herein reported. Importantly, the need for a rigid tether in these reactions has been obviated. The ease-of-synthesis and viability of substrates bearing flexible backbones has permitted for diastereoselective variants as well. We demonstrated the utility of this methodology with the formation of pyrrolidones, piperidinones, isoindolinones, and sultams. Furthermore, subsequent transformation of these motifs into medicinally relevant molecules is also demonstrated. A double crossover 13C-labeling experiment is consistent with a fully intramolecular cyclization mechanism. Deuterium labeling experiments support a mechanism involving syn-addition across the alkene.

The cyclization of an alkene-bearing cyclopentanone to a [2.2.1]-norcamphor ring system is described. The reaction is catalyzed by a combination of rhodium and Bronsted acid. Control experiments indicate that both are needed for acceptable yield. Control experiments with bulky base additives show that rhodium promotes alkene isomerization, likely the first step of this cascade reaction, and that rhodium alone does not promote cyclization. Cyclization is promoted by Bronsted acid in a Prins-type cyclization and carbocation rearrangement process. Trace Bronsted acid present in commercial samples of Rh(cod)2OTf is likely responsible for the observed reaction. Indeed, the norcamphor product can be obtained simply with strong acid, presumably initiated by acid-promoted alkene isomerization. Since our initial motivation for this work was the development of rhodium catalysts for the activation of C–C bonds adjacent to ketones, this communication serves to identify other, perhaps less obvious, pathways for the reactions of unsaturated ketone compounds by the action of rhodium catalysts.

Sparked by the strategy of pillared-layer MOFs, three formate coordination polymers, {[Ni(2)(HCO(2))(3)(L)(2)](NO(3)).2H(2)O}(infinity) (1), {[Co(2)(HCO(2))(3)(L)(2)](HCO(2)).2H(2)O}(infinity) (2), and {[Cu(2)(HCO(2))(3)(L)(2)](HCO(2)).2H(2)O}(infinity) (3), have been synthesized by employing the rodlike ligand 4,4'-bis(imidazol-1-yl)biphenyl (L) as the pillar. Structural analysis indicates that the title complexes 1-3 are isostructural compounds, which possess metal-formate 2D layers perpendicularly pillared by the ligand L to afford a 3D open framework. This is an interesting example of a Kagome lattice based on the formate mediator. Moreover, the formate anion of this 2D Kagome layer exhibits various bridging modes: anti-anti, syn-anti, and 3.21 modes. Their magnetic measurements reveals that only complex 1 presents the spin canting phenomenon, while its isostructural Co(II) and Cu(II) complexes are simply paramagnets with antiferromagnetic coupling.

The title reaction affords functionalized indanones (II) in moderate to high yields and tolerates substitution at various positions on the aromatic ring including electron donating and electron withdrawing groups.

Reported here is a palladium catalyzed intramolecular acylcyanation of alkenes using α-iminonitriles. Through this method, highly functionalized indanones are synthesized in moderate to high yields using Pd(PPh3)4, without need for any additional ligands, and a common Lewis acid (ZnCl2). Additionally, the reaction tolerates substitution at various positions on the aromatic ring including electron donating, and electron withdrawing groups.