Chiral Tetraazamacrocycles Having Four Pendant-Arms
摘要:
chiral tetraazamacrocycle 9 having four pendant-arms was synthesized by repeating ring opening of an Ns-aziridine with secondary amines, followed by macrocyclization. The structure of 9 has been determined by single crystal X-ray diffraction analysis and NMR studies. Sugar-hybrid molecules 12a-12f were synthesized based on the scaffold 9. NMR study showed that 12a-12f keep the similar conformation as 9 in solution.
Chiral Tetraazamacrocycles Having Four Pendant-Arms
摘要:
chiral tetraazamacrocycle 9 having four pendant-arms was synthesized by repeating ring opening of an Ns-aziridine with secondary amines, followed by macrocyclization. The structure of 9 has been determined by single crystal X-ray diffraction analysis and NMR studies. Sugar-hybrid molecules 12a-12f were synthesized based on the scaffold 9. NMR study showed that 12a-12f keep the similar conformation as 9 in solution.
Enantioselective organocatalytic α-sulfamidation of aldehydes using sulfonyl azides
作者:Raymond J. McGorry、Stacey K. Allen、Micha D. Pitzen、Thomas C. Coombs
DOI:10.1016/j.tetlet.2017.10.063
日期:2017.12
Enantioselective organocatalytic α-sulfamidation of unbranched aldehydes is described using MacMillan’s second-generation imidazolidinone catalyst and o-nitrobenzenesulfonyl azide. The reactions are highly stereoselective (89.9–96.3% ee) with yields up to 71%. A strong correlation between aldehyde structure and product yield was found to exist, with 3-arylpropanals providing the best results. Application