No abstract

[reaction: see text] A general, efficient, and experimentally simple method for the generation of sulfenate salts has been developed using beta-sulfinylesters as substrates. The process is based on a retro-Michael reaction, initiated by deprotonation at low temperature. Upon treatment with alkyl halides, the liberated sulfenates are subsequently converted into sulfoxides in good to excellent yield. Extension of the methodology to an unprecedented access to nonracemic sulfoxides by introduction of an enantiopure ligand, (-)-sparteine, is also described.

The ligand exchange reaction between Au38(2-PET)24 (2-PET: 2-phenylethanethiolate) clusters and enantiopure planar chiral [2.2]paracyclophane-4-thiol 1 (PCP-4-SH) was studied using High Performance Liquid Chromatography (HPLC) and mass spectrometry. It is shown that even at the initial stage of the reaction at least three out of the four symmetry-unique sites are exchanged leading to different regioisomers of composition Au38(2-PET)23(PCP-4-S)1. Using HPLC it was possible to isolate one specific regioisomer. The latter is stable at room temperature and at slightly elevated temperatures. However, at 80° C the adsorbed thiolate (PCP-4-S) moves between different symmetry-unique sites. These observations have implications for the preparation of mixed ligand shell clusters with specific ligand patterns