DFT Approach for Predicting C NMR Shifts of Atoms Directly Coordinated to Pt: Scopes and Limitations.

In this study, comparative analysis of calculated and experimental C NMR shifts for a wide range of model platinum complexes showed that, on the whole, the theory reproduces the experimental data well. The chemical shifts of carbon atoms directly bonded to Pt can be calculated well only within the framework of the fully relativistic matrix Dirac-Kohn-Sham (mDKS) level ( = 0.9973, = 3.

NMR "Finger Prints" of N-Heterocyclic Carbenes, DFT Analysis: Scopes and Limitations.

The scopes and limitations of theoretical methods for estimating various NMR metrics of NHCs are considered on a wide range of model NHCs and their derivatives, using a number of computational approximations. On the whole, the most reliable, from the point of view of predictability and insusceptibility to additional effects, are P/C NMR shifts of NHC-phosphinidene adducts and C CSs of carbenes themselves. The method based on the analysis of Se CS NHC-selenoureas has some limitations since the observed NMR parameters can also be modulated by exchange effects due to their formation with non-classical hydrogen bonds.

DFT Calculations of P NMR Chemical Shifts in Palladium Complexes.

In this study, comparative analysis of calculated (GIAO method, DFT level) and experimental P NMR shifts for a wide range of model palladium complexes showed that, on the whole, the theory reproduces the experimental data well. The exceptions are the complexes with the P=O phosphorus, for which there is a systematic underestimation of shielding, the value of which depends on the flexibility of the basis sets, especially at the geometry optimization stage. The use of triple-ζ quality basis sets and additional polarization functions at this stage reduces the underestimation of shielding for such phosphorus atoms.

Synthesis and Mechanistic Insights of the Formation of 3-Hydroxyquinolin-2-ones including Viridicatin from 2-Chloro-,3-diaryloxirane-2-carboxamides under Acid-Catalyzed Rearrangements.

-Benzyl-2-chloro-,3-diaryloxirane-2-carboxamides, easily obtained from aromatic aldehydes and anilides of dichloroacetic acid under Darzens condensation conditions, proved to be excellent starting compounds for the synthesis of 3-hydroxyindolin-2-ones, cyclohepto[]pyrrole-2,3-diones, and 1-azaspiro[4.5]deca-3,6,9-triene-2-ones via the C(sp)-C(sp) bond formation in the first case and C(sp)-C(sp) bond formation in the second and third cases. Under optimized reaction conditions, 3-hydroxyindolin-2-ones are obtained in a one-pot process, which involves the treatment of -benzyl-2-chloro-,3-diaryloxirane-2-carboxamides with CFCOH or AcOH/HSO.