SUPPORTING INFORMATION CONTENTS1. X-Ray diffraction 1 2. Characterization data of compounds 3 2 3. Copies of 1 H, 13 C, 31 P, and 77 Se NMR spectra of all new compounds 7 4. 31 P NMR monitoring of the P-Se bond splitting using TBAF 29 5. Crystal data and structure refinement for 3l (Table S1) 30 6. Two-dimensional intermolecular H-bonding network in 3l (Figure S58) 31 7. Cif file for 3l (CCDC 888468) 32
X-Ray diffractionThe experimental diffraction data were collected on a KM4CCD (Oxford Diffraction, now part of Varian) kappa-geometry diffractometer equipped with a Sapphire-2 area detector. An enhanced X-ray Mo Ka radiation source with a graphite monochromator was used. The data reduction was conducted using CrysAlis software package. 1 Structure solution and final refinement were carried out using the SHELX-97 program package. 2 Packing diagrams were prepared using Mercury visualization software. 3 The parameters of the crystal cell, the results of the refinement of the structure of 3l are shown in Table S1. Crystallographic data for compound 3l has been deposited with the Cambridge Crystallographic Data Centre as supplementary publication number CCDC 888468. The data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/structures.