Motivated by the recent achievements in the realization of strongly correlated and topological phases in twisted van der Waals heterostructures, we study the low-energy properties of a twisted bilayer of nodal superconductors. It is demonstrated that the spectrum of the superconducting Dirac quasiparticles close to the gap nodes is strongly renormalized by twisting and can be controlled with magnetic fields, current, or interlayer voltage. In particular, the application of an interlayer current transforms the system into a topological superconductor, opening a topological gap and resulting in a quantized thermal Hall effect with gapless, neutral edge modes. Close to the "magic angle," where the Dirac velocity of the quasiparticles is found to vanish, a correlated superconducting state breaking time-reversal symmetry is shown to emerge. Estimates for a number of superconducting materials, such as cuprate, heavy fermion, and organic nodal superconductors, show that twisted bilayers of nodal superconductors can be readily realized with current experimental techniques.

Pyridines undergo site selective cross-coupling with secondary phosphine chalcogenides (oxides, sulfides, and selenides) in the presence of acylphenylacetylenes under metal-free mild conditions (70-75 °C, MeCN) to afford 4-chalcogenophosphoryl pyridines in up to 71% yield. In this new type of SNHAr reaction acylacetylenes act as oxidants, being stereoselectively reduced to the corresponding olefins of the E-configuration.

Terminal acylacetylenes, typical electron-deficient acetylenes, drive SNH cross-coupling of pyridines with secondary phosphine chalcogenides under metal-free mild conditions (20–75 °C) to afford 4-chalcogenophosphorylpyridines in up to 70% yield. The reaction...

Acridine adds secondary phosphine chalcogenides HP(X)R 2 (X = O, S, Se; R = Ar, ArAlk) under catalystfree conditions at 70−75 °C (both in the presence and absence of the electron-deficient acetylenes) to give 9chalcogenophosphoryl-9,10-dihydroacridines in 61−94% yields. This contrasts with pyridines, which under similar conditions undergo an S N H Ar reaction, wherein electron-deficient acetylenes play the role of oxidants. For acridine, the S N H Ar step has been accomplished by the oxidation of the intermediate 9phosphoryl-9,10-dihydroacridines (X = O) with chloranil.

Quinolines react with acylacetylenes and secondary phosphine chalcogenides at 20–75 °C to afford N-acylvinyl-2­(1)-chalcogenophosphoryldihydroquinolines in good and excellent yields. Unlike the pyridine-derived similar intermediates, which eliminate E-alkenes to give aromatic chalcogenophosphorylpyridines, thereby completing SN HAr reaction, with quinolines, the reaction stops at the formation of the above phosphorylated N-acylvinyl-dihydroquinolines, thus representing a pendant SN HAr process. This reaction opens a one-pot atom-economic single-step access to pharmaceutically targeted phosphorylated functionalized dihydroquinolines and isoquinolines.

An efficient catalyst-and solvent-free method for the synthesis of tertiary α-hydroxyphosphine chalcogenides, via the almost quantitative addition of secondary phosphine chalcogenides to diverse aldehydes under mild conditions (20-52 °C, from 10 min to 5 h), is reported.

Quinolines undergo catalyst-free double CH-functionalization upon treatment with secondary phosphine oxides (70–75 °C, 20–48 h) followed by oxidation of the intermediate 2,4-bisphosphoryltetrahydroquinolines with chloranil. The yields of the target 2,4-bisphosphorylated quinolines are up to 77%. Thus, a double-SN HAr reaction sequence in the same molecule of quinoline has been realized. In the case of 2,4-bisphenylphosphoryltetrahydroquinolines, the aromatization occurs with elimination of one molecule of diphenylphosphine oxide to afford the products of monofunctionalization, 4-diphenylphosphorylquinolines, in 40–45% yields.

The effect of chalcogenophosphoryl fragments on the anodic oxidation of 9-chalcogenophosphoryl-9,10-dihydroacridines was studied in detail. The data of X-ray structural analysis, quantum chemical calculations and cyclic voltammetry obtained for these compounds provide an explanation of the observed features. The direct electrochemical phosphorylation of acridine was first carried out successfully.