Intermolecular Dearomatization of Naphthalene Derivatives by Photoredox-Catalyzed 1,2-Hydroalkylation.

An intermolecular hydroalkylative dearomatization of naphthalenes with commercially available α-amino acids is achieved via visible-light photoredox catalysis. With an organic photocatalyst, a series of multi-substituted 1,2-dihydronaphthalenes are obtained in good-to-excellent yields. Intriguingly, by tuning the substituents at the C2 position of naphthalenes, formal dearomative [3+2] cycloadditions occur exclusively via a hydroalkylative dearomatization-cyclization sequence. This overall redox-neutral method features mild reaction conditions, good tolerance of functionalities, and operational simplicity. Diverse downstream elaborations of the products are demonstrated. Preliminary mechanistic studies suggest the involvement of a radical-radical coupling pathway.

Asymmetric Dearomatization of Indole Derivatives with N-Hydroxycarbamates Enabled by Photoredox Catalysis.

Dearomatization of indoles provides efficient synthetic routes for substituted indolines. In most cases, indoles serve as nucleophiles. Reported here is an asymmetric dearomatization reaction of indole derivatives that function as electrophiles. The combination of a photocatalyst and chiral phosphoric acid open to air unlocks the umpolung reactivity of indoles, enabling their dearomatization with N-hydroxycarbamates as nucleophiles. A variety of fused indolines bearing intriguing oxy-amines were constructed in excellent yields with moderate to high enantioselectivities. Mechanistic studies show that the realization of two sequential single-electron transfer oxidations of the indole derivatives is key, generating the configurationally biased carbocation species while providing the source of stereochemical induction. These results not only provide an efficient synthesis of enantioenriched indoline derivatives, but also offer a novel strategy for further designing asymmetric dearomatization reactions.

Perchloratobis[1-(1,10-phenanthrolin-2-yl)-2-pyridone]zinc(II) perchlorate.

In the title mononuclear complex, [Zn(ClO(4))(C(17)H(11)N(3)O)(2)]ClO(4), the Zn(II) ion is coordinated in a distorted octa-hedral geometry. The dihedral angles between the pyridine rings and the mean planes of the 1,10-phenanthroline ring system in each of the 1-(1,10-phenanthrolin-2-yl)-2-pyridone (PP) ligands is 24.51 (10)° for the tridendate PP ligand and 73.55 (6)° for the bidentate PP ligand. Within the mol-ecule there is a weak π-π inter-action between the pyridine ring of the bidentate ligand and the 1,10-phenanthroline ring system of the tridendate ligand with a centroid-centroid distance of 3.6383 (19) Å.

Diaqua-(1,10-phenanthrolin-2-ol)nickel(II) dinitrate.

In the mononuclear title complex, [Ni(C(12)H(8)N(2)O)(2)(H(2)O)(2)](NO(3))(2), the Ni(II) ion is coordinated in a distorted octa-hedral geometry. The dihedral angle between the two mean planes defined by the phenanthroline ligands is 88.26 (6)°. Intra- and intermolecular O-H⋯O hydrogen bonds between the cation and the anions lead to the formation of a layered arrangement parallel to (010).