All NMR spectra were recorded at 298 K unless otherwise specified. Chemical shifts are stated in ppm relative to the solvent residual signals ( .24 ( 1 H) and 77.00 ( 13 C) for CDCl 3 and 2.50 ( 1 H) and 39.52 ( 13 C) for DMSO-d 6 ). 13 C{ 1 H} NMR spectra are recorded in a J-modulated mode. HRMS was acquired on a Bruker Maxis ESI oa-RTOF mass spectrometer (maXis ESI-Qq-TOF mass spectrometer, Bruker Daltonics, Bremen, Germany) using a quadrupole analyzer as ion guide. Chromatography was performed on a Biotage Isolera One flash purification system using self-packed SiO 2 cartridges. The SiO 2 used was Macherey-Nagel silica gel 60M (particle size 40-63 µm). Also for additional separation of amines and urea derivatives self-packed cartridges of Merck LiChrosorb NH 2 material were used (particle size . TLC were performed on Macherey-Nagel TLC aluminium sheets with a 0.20 mm layer of silica gel 60 with F254 fluorescence indicator. Heptane, DCM and EtOAc were distilled before use, dry DCM was distilled from CaH 2 , dry THF was distilled from sodium benzophenone ketyl under Argon and DMF was distilled from CaH 2 under reduced pressure and stored with molecular sieve 4 Å. Et 3 N was distilled and stored under Argon prior to use. Other chemicals were bought in reagent grade or better and were used as they arrived. dinaphtho oxa thia azacycloundecine 13,13-dioxide 2: