Organothio sulfonyl carbenes 3 have been generated via ylid thermolysis or via α-elimination starting from α-chloro α-organothio sulfones and their derivatives. They have been captured by suitable nucleophilic trapping reagents (diazomethane, enol ethers, and others). Their nucleophilic carbenoid precursors could be trapped by an electrophilic olefin (ketene dithioacetal S,S-dioxides as Michael acceptors). Stable carbene Z-dimers could be obtained under various conditions. Bromine catalyzed isomerization to E-isomers proved to be reversible.

No abstract

ChemInform Abstract Alkoxy arylsulfonyl carbenes such as (II) are generated by α-elimination of hydrogen halide from (alkoxy)(halo)methyl aryl sulfones such as (I). Their self-decomposition as well as trapping reactions with diazoalkanes, e.g. (VIII), and with appropriate olefins, e.g. (X) are studied.

1994intermediates intermediates (and their reactions) O 0190 -069Donor Substituted Sulfonyl Carbenes. Part 2. Organothio Sulfonyl Carbenes.-Organothio sulfonyl carbenes, which are prepared in situ by decomposition of ylides like (I) or α-elimination from chloro sulfones of type (IV), can be trapped by enol ethers, styrenes and diazo compounds to afford cyclopropanes such as (III) and (VI) or pyrazoles like (VIII). In the absence of trapping reagents compounds of type (IX) are formed. Treatment of (IVa) with CH2N2 under PTC conditions leads to the cyclopropane (XI) and the Michael adduct (XII) (yield not given) via coupling of the reactive carbanion of (IVa) with electrophilic ketene dithioacetal-S,S-dioxide generated in situ. In addition, it is shown that organothio sulfones such as (IV) react with BuLi and Tms-Cl, I2, or phenyl glyoxal giving carbene Z-dimers like ( XIII) which easily undergo reversible Z/E isomerization. -(SCHANK, K.; ABDEL WAHAB, A.-M. A.; BUEGLER, S.; EIGEN, P.; JAGER, J.; JOST, K.; Tetrahedron 50 (1994) 12,