An Assessment of Electrophilic N-Transfer of Oxaziridine with Different 2-, 3-, and 4-Carbon Donor-Acceptor Substrates to Furnish Diverse N-Containing Heterocycles in a Single Step
作者:Asit Ghosh、Vatan Chawla、Prabal Banerjee
DOI:10.1002/ejoc.201900589
日期:2019.6.23
Exhibition of the electrophilic N‐transfer ability of oxaziridine as a complementary approach for direct access to an array of diversely functionalized N‐containing heterocycles from readily available oxaziridines and carbon substrates. The electronic factor of different donor substituents present on different push–pull carbon substrates significantly influences the feasibility of the amination reaction
The first highlydiastereoselective and enantioselective catalytic formal [4 + 3] cycloaddition of 1,1-cyclobutane diester with nitrone has been developed. Sterically hindered chiral SaBOX/Cu(II) complex promotes the reaction efficiently with a broad substrate scope, producing a range of multifunctionalized optically active 1,2-oxazepanes with excellent stereocontrol (up to >99/1 dr and 97% ee).
Copper catalyzed enantioselective [4 + 2] annulations of D‐A cyclobutanes and aldehydes have been developed. In the presence of a side arm modified chiral bisoxazoline (SaBOX) ligand, the [4 + 2] annulations proceeded smoothly with a broad substrate scope. 22 examples were studied, leading to the corresponding products with various functional groups in 41%–99% yields with >99/1 dr and 90%–96% ee. The