Torsional angles in 6,6?-bridged atropoisomeric biphenyls control the electrophilic substitution with phthalimidesulfenyl chlorid

The reaction of phthalimidesulfenyl chloride with 2,2',6,6'-hydroxylated biphenyls allowed the preparation of 3- and/or 3,3'-N-thiophthalimide derivatives which can be easily transformed into the corresponding thiols and/or disulfides. Mono- or bis-substitution, as well as the regiochemistry of the sulfenylation, are predictable as a function of the substituents on the biphenyl unit and the lenght of the 6,6'bridge.