Rhodium-catalyzed annulation of hydrazines with vinylene carbonate to synthesize unsubstituted 1-aminoindole derivatives.

Herein, we describe rhodium-catalysed C-H bond activation for [3 + 2] annulation using hydrazide and vinylene carbonate, providing an efficient method for synthesising unsubstituted 1-aminoindole compounds. Characterised by high yields, mild reaction conditions, and no need for external oxidants, this transformation demonstrates excellent regioselectivity and a wide tolerance for various functional groups.

Synthesis of C3-sulfone substituted naphthols via rhodium(III)-catalyzed annulation of sulfoxonium ylides with alkynylsulfones.

C-H activation of sulfoxonium ylides catalyzed by rhodium(iii) with subsequent annulation by alkynylsulfones was accomplished. This methodology offers a step-economical approach for assembling C3-sulfone-substituted naphthols with a high level of regioselectivity that is complementary to previous protocols. The approach has an extensive substrate spectrum and broad functional group tolerance.

Stabilities and novel electronic structures of three carbon nitride bilayers.

We predict three novel phases of the carbon nitride (CN) bilayer, denoted α-C2N2, ß-C2N2 and γ-C4N4, respectively. All of them consist of two CN sheets connected by C-C covalent bonds. The phonon dispersions reveal that all these phases are dynamically stable, because no imaginary frequency is present. The transition pathway between α-C2N2 and ß-C2N2 is investigated, which involves bond-breaking and bond-reforming between C and N. This conversion is difficult, since the activation energy barrier is 1.90 eV per unit cell, high enough to prevent the transformation at room temperature. Electronic structure calculations show that all three phases are semiconductors with indirect band gaps of 3.76/5.22 eV, 4.23/5.75 eV and 2.06/3.53 eV, respectively, by PBE/HSE calculation. The ß-C2N2 has the widest band gap among the three phases. All three bilayers can become metallic under tensile strain, and the indirect gap of γ-C4N4 can turn into a direct one. γ-C4N4 can become an anisotropic Dirac semimetal under uniaxial tensile strain. Anisotropic Dirac cones with high Fermi velocity of the order of 105 m/s appear under 12% strain. Our results suggest that the three two-dimensional materials have potential applications in electronics, semiconductors, optics and spintronics.

Structure revision of aspergicin by the crystal structure of aspergicine, a co-occurring isomer produced by co-culture of two mangrove epiphytic fungi.

The structure of aspergicin (1), an antibacterial alkaloid produced by co-culture of two marine-derived mangrove epiphytic fungi, were revised by the co-occurring isomer named as aspergicine (2), whose structure was determined on the basis of spectroscopic analysis and X-ray crystallography.

Rh(III)-Catalyzed C7-Thiolation and Selenation of Indolines.

The rhodium(III)-catalyzed intermolecular C7-thiolation and selenation of indolines with disulfides and diselenides were developed. This protocol relies on the use of a removable pyrimidyl directing group to access valuable C-7 functionalized indoline scaffolds with ample substrate scope and broad functional group tolerance.