ABSTRACT
Sulfoxides are widely used in the pharmaceutical industry and as ligands in asymmetric catalysis. However, the efficient asymmetric synthesis of this structural motif remains limited. In this study, we disclosed a Ni-catalyzed enantioconvergent reaction that utilizes both racemic allenyl carbonates and ß-sulfinyl esters. Our method employs cheap and more sustainable Ni(II) as a precatalyst and successfully overcomes the challenging poisoning effect and instability of sulfenate generated in situ. This enables the synthesis of a series of dienyl sulfoxides with enantioselectivity of up to 98 % ee. The product exhibits tremendous potential in various applications, including diastereoselective Diels-Alder reactions, coordination with transition metals, and incorporation into medicinal compounds, among others. Using a combination of experimental and computational methods, we have uncovered an interesting associated outersphere mechanism that contrasts with conventional mechanisms commonly observed in asymmetric transition metal catalysis.
ABSTRACT
Epidemic cerebrospinal meningitis (meningococcal meningitis) is an acute respiratory infectious disease with high mortality and serious sequelae. Meningococcal vaccine is an effective measure to prevent and control meningococcal meningitis. At present, group B meningococcal meningitis has become the main prevalent serum group in the world, including China. Meningococcal ACYW and other vaccines are mainly composed of capsular polysaccharides, while the main component of group B meningococcal vaccine is protein, including outer membrane vesicles (OMV) and recombinant protein vaccine. The methods for evaluating the immunogenicity of group B meningococcal vaccine include hSBA and alternative methods such as meningococcal antigen typing system (MATS), flow cytometric meningococcal antigen surface expression assay (MEASURE), genetic meningococcal antigen typing system (gMATS) and bexsero antigen sequence type (BAST). The evaluation of vaccine immunogenicity is the basis of vaccine development and clinical trial research, However, at present, there is no group B meningococcal vaccine in China. Therefore, in this paper, the research progress of immunogenicity evaluation of group B meningococcal vaccine has been reviewed, in order to provide technical guidance for the research and development of group B meningococcal vaccine, immunogenicity evaluation and clinical trial research in China.
