A Concise, Modular Synthesis of Chiral Peraza-Macrocycles Using Chiral Aziridines

Abstract

[reaction: see text] Novel chiral peraza-macrocycles were synthesized from chiral aziridines as a common building block. Efficient syntheses of chiral [26]-N(6), [12]-N(4), [9]-N(3), and [14]-N(4) systems were accomplished.

Asymmetric cyclopropanation of olefins catalysed by Cu(i) complexes of chiral pyridine-containing macrocyclic ligands (Pc-L*)

“…There are two main steps involved in the synthesis. Firstly, ethanolamine or (L)-valinol was reacted with 2 equivalents of tosyl chloride in the presence of a weak base to afford aziridine derivatives 1a and 1b, 6 respectively. Use of triflic anhydride in the reaction with valinol in dichloromethane afforded the aziridine 1c.…”

“…5,6 The synthesized ligands were used to prepare the corresponding paramagnetic metal ion complexes, after introduction of the appropriate pendant arms on the nitrogen atoms. 5 A few years ago, our group reported the synthesis and characterisation of copper(I) complexes of new pyridine containing tetraazamacrocyclic ligands 7 and preliminary results on their use as catalysts in asymmetric cyclopropanation reactions.…”

A General Method for the Preparation of Chiral TREN Derivatives

“…By a recently published method these compounds were obtained in one step in 82 and 73 % yield from commercially available (S)-valinol (3a) and (S)-alaninol (3b), respectively, using tosyl chloride, triethylamine, and DMAP. [18] A two-step procedure, using two equivalents of tosyl chloride, was reported to result in even higher yields of the same compounds, 90 and 88 %. [19] In our hands, this latter procedure afforded 2a and 2b in considerably lower yields.…”

NMR investigation into the dynamic behaviour of a novel C2‐symmetric macrocyclic ligand

“…The Arrhenius plot gave a value for the activation energy E a D 43. 3 In the lower temperature spectra, that measured at 213 K shows the best resolution. As the temperature is further decreased (see Fig.…”