Generation and Rearrangement of Some Spirocycloaliphatic Thiosulfines and Dithiiranes

Abstract

The flash‐vacuum pyrolysis of selected dispirodicycloaliphatic 1,2,4‐trithiolanes was studied by using matrix isolation techniques. The formation of thiosulfines and dithiiranes along with the corresponding thioketones was detected spectroscopically and confirmed by comparison with computed spectra. In the case of tetramethylcyclobutanone 1,2,4‐trithiolane, the thermal formation of the dithiolactone was observed. Pyrolysis of the (dichloro)tetramethylcyclobutane derivative resulted only in the formation of a mixture of the thiosulfine and dithiirane. In this case, conversion into the corresponding dithiolactone could be achieved photochemically. The dispirodiadamantane derivative gave a mixture of the respective thiosulfine and dithiirane but no dithiolactone could be detected in the mixture. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

Reaction of 3,3,5,5‐Tetraphenyl‐1,2,4‐trithiolane with Pt0(bisphosphane)(η2‐nbe) Complexes Bearing Bridged Bisphosphane Ligands with Various Bite Angles

“…Huisgen and Rapp used the thermal cycloreversion of 3,3,5,5‐tetraphenyl‐1,2,4‐trithiolane ( 1 ) to generate diphenylthiosulfine ( 3 ) and confirmed its existence by interception reactions with diverse dipolarophiles 2. In recent years, developments in flash vacuum pyrolysis (FVP) allowed the study of thiosulfines in an argon matrix at 10 K3 and provided more insight into the rearrangement of thiosulfines4 to dithiiranes or dithiocarboxylates,3a,3c as well as [1,4]‐H shifts to form vinyl disulfanyls 3b…”

Thermal Reactions of Regioisomeric 1,2,4‐Trithiolane S‐Oxides

“…The ratio of 4a and 5a, formed in the gas phase, was shown to depend on the temperature and the lower the temperature, the less of the cyclic product forms. In comparison with earlier reports [4,5,9] the pyrolysis temperature applied in the Figure 4. The IR spectrum of matrix-isolated (argon, 10 K) high-vacuum flash pyrolysis products of 1,2,4-trithiolane 1-S-oxide (9a) generated at 700°C.…”

“…The latter is believed to form from the thiosulfine 4b via a 1,4-H shift (Scheme 2). [5] Spirocycloaliphatic 1,2,4-trithiolane 3c was reported to undergo gas phase thermolysis yielding a mixture of thiosulfine 4c, the spirocyclic dithiirane 5c, and dithiolactone 7.…”

Organic and Coordination Chemistry of 1,2,4‐Trithiolanes

“…The corresponding dithiiranes 16b and 16c (Figure ) were also detected in Ar‐matrices at 10 K after gas‐phase pyrolysis of 1,2,4‐trithiolanes 1f and 1m , respectively …”