10.1080/10426507.2016.1255621
The research focuses on the development of two methodologies for synthesizing sulfur heterocycles (S-heterocycles) and mixed nitrogen-sulfur heterocycles (N,S-heterocycles) through metal-mediated domino reactions. The first methodology involves a cyclocarbopalladation/cross-coupling domino process, utilizing propargyl sulfides or ynethioethers as starting materials and Pd(PPh3)4 as a catalyst, with Stille or Suzuki-Miyaura coupling partners like 2-furyl, 2-thienyl, allyl, and vinyl tributylstannanes, or arylboronic acids. This approach yields benzene-fused five- or six-membered sulfur heterocycles with a stereodefined tetrasubstituted exocyclic double bond. The second methodology is a three-component domino reaction between 2-aminophenyl disulfide, copper cyanide (CuCN), and an electrophile, which accesses N-substituted 2-amino benzothiazoles. The experiments also explore the synthesis of N-substituted 2-imino benzothiazoles using N-protected 2-aminoaryl disulfides as precursors. The analyses used to confirm the structures of the synthesized compounds include X-ray crystallography, with crystallographic data deposited at the Cambridge Crystallographic Data Center.
10.1016/j.tetlet.2007.01.145
The research focuses on the stereoselective synthesis of trans-olefins through the copper-mediated SN2' reaction of vinyl oxazines with Grignard reagents, using CuCN as a catalyst. The study explores the high trans selectivity observed in the formation of double bonds with a variety of RMgX reagents and combines this with a regioselective asymmetric aminohydroxylation reaction to provide an efficient route for the asymmetric synthesis of DD-threo-N-acetylsphingosine, a sphingosine derivative with biological significance. The experiments involved the synthesis of vinyl oxazines, their reaction with Grignard reagents in the presence of CuCN, and the analysis of the resulting products using techniques such as 1H and 13C NMR spectroscopy to determine the trans:cis selectivity and confirm the structure of the synthesized compounds. The research also investigated the influence of the stereochemistry at the allylic position on the reaction's stereochemical outcome and tested the generality of the SN2' reaction with Grignard reagents of varying chain lengths.
T+,
N,
T
T+:Very toxic;
