Preparation and Cycloaddition Chemistry of Thio- and Selenocarbonyls Derived from Reaction of Elemental Sulfur and Selenium with Stabilized α-Halo Anions

Article abstract of DOI:10.1016/0040-4039(91)80114-L

Reaction of diethyl chloromalonate with Cs2CO3 in the presence of elemental S8 or Se_n generates the corresponding diethyl thioxo- or selenoxomalonates which are subsequently trapped in situ with various 1,3-dienes.Similarly, the chalcogen carbonyls can be prepared from other halogenated compounds using DBU as the base and effectively trapped in Diels-Alder fashion with 2,3-dimethyl-1,3-butadiene (Table 2).