General NMR Spectra were recorded on two different Bruker spectrometers (Bruker Biospin, Billerica, MA, USA): A Bruker AVIII 400 spectrometer operating at 400.27 MHz ( 1 H), 100.66 MHz ( 13 C) and 162.04 MHz ( 31 P) used for standard spectra and a Bruker AVIII 600 operating at 600.25 MHz ( 1 H), 150.95 MHz ( 13 C) and 242.97 MHz ( 31 P). All NMR spectra were recorded at 298 K unless otherwise specified. Chemical shifts are stated in ppm relative to the solvent residual signals. The solvents were calibrated to 7.24 ( 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, unless otherwise noted, 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.