Pd-catalyzed Asymmetric Cycloaddition Of Vinylethylene Carbonates With Isocyanates

Optically activeβ-amino alcohols are prevalent motifs in a wide variety of im-portant medicinally relevant agents and biologically active natural products, also opti-cally activeβ-amino alcohols have N atoms and O atoms, they are good coordinationatoms. with a variety of elements to form the complex and become excellent chiral cat-alyst. The catalyst has high stereoselectivity and catalytic efficiency. The catalyst stereolead to the main products’ configuration. So optical activity β-amino alcohols canalso serve as important chiral auxiliaries. Because of its unique physiological function,synthetic organic chemists will spare no effort to explore different synthesis of chiralβamino alcohols. Despite persistent efforts aimed at developing asymmetric catalyticmethods for the synthesis of enantiomerically enriched β-amino alcohols, the catalyticapproaches for enantioselective construction of quaternary amino alcohols, more spe-cifically β,β-disubstituted β-amino alcohols are largely unexplored. quaternary vinyl-glycinols become more challenging not only because the vinyl group is a valuablefunctional group in organic transformations, but also the framework is highly useful forthe synthesis of biologically important quaternary α-amino acids such as quaternaryvinlyglycines and-substituted serines. Nevertheless, so far, there is only two examplesof catalytic construction of quaternary vinylglycinols was reported, However, the sub-strate was only limited to isoprene monoxide. There are many challenges in the area ofsynthesizing quaternary vinylglycinols,So it deserves more research and attention.we have developed an efficient method for enantioselective construction of qua-ternary vinyloxazolidinones via Pd-catalyzed asymmetric cycloaddition reaction ofreadily available quaternary VECs with isocyanates. The reactions proceeded smoothlyin the presence of Pd2(dba)3CHCl3and Segphos under mild and neutral conditions toafford quaternary vinyloxazolidinones in high yields (up to95%) with excellent ena n-tioselectivities (8699%ee). In addition, the practical value of this process was demo n-strated by gram-scale synthesis. The quaternary vinyloxazolidinone could be conve n-iently converted to the quaternary vinylglycinol, an important chiral building block forbiologically valuable compounds. This paper provides an efficient, convenient, practi-cal synthesis method for chiral quaternary vinylglycinols.