Direct Episulfidation of Alkenes and Allenes with Elemental Sulfur and Thiiranes as Sulfur Sources, Catalyzed by Molybdenum Oxo Complexes
作者:Waldemar Adam、Rainer M. Bargon、Wolfdieter A. Schenk
DOI:10.1021/ja029292p
日期:2003.4.1
4 and allenes 6, for which elemental sulfur, phenylthiirane, or methylthiirane have been employed as sulfur sources to afford the corresponding episulfides 5 and 7. The most effective catalytic episulfidation system to date is the combination of the dithiophosphate-ligated oxo complex 1b and phenylthiirane (Ibeta). This metathesis process is efficient enough to convert usually reluctant alkenes (cyclopentene
1′-dithiobis(1H-1,2,4-triazole) 4 at −15 °C to form the corresponding thiiranes in moderate to good yields. The thiiranations of anti- and syn-9,9′-bibenzonorbornenylidenes and cis- and trans-cyclooctenes with 4 proceeded with retention of configuration of the starting alkenes.
八个烯烃在-15°C下与1,1'-二硫代双(1 H -1,2,4-三唑)4反应,以中等至良好的产率形成相应的噻喃。的thiiranations抗和-顺式- bibenzonorbornenylidenes -9,9'-和顺-和反式与-cyclooctenes 4进行与起始烯烃的结构的保持。
Concerning the synthesis and enantioselective rearrangements of episulfoxides
作者:Alexander J. Blake、Paul A. Cooke、Jackie D. Kendall、Nigel S. Simpkins、Susan M. Westaway
DOI:10.1039/a908391j
日期:——
A novel synthesis of episulfoxides having the norbornane skeleton is possible by use of a rhodium catalyst to effect SO transfer from trans-stilbene episulfoxide to norbornene or norbornadiene. Analogous Rh2(OAc)4 catalysed sulfur transfer to these alkenes is also possible using propylene sulfide as the sulfur source. These methods did not give useful yields of products with alternative types of alkene substrate.
A novel type of chiral lithium amide base reaction, involving the rearrangement of certain types of symmetrical ring-fused episulfoxides, gives alkenyl sulfoxide products in up to 88% ee. The structures of the products, including absolute stereochemistry, were assigned based on X-ray crystal structure determinations.
p
Thioozonide decomposition. Sulfur and oxygen atom transfer. Evidence for the formation of a carbonyl O-sulfide intermediate
作者:M. G. Matturro、R. P. Reynolds、R. V. Kastrup、C. F. Pictroski
DOI:10.1021/ja00270a058
日期:1986.5
mechanism involving a carbonyl sulfide 4 as an intermediate along the sulfur expulsion pathway to 3c; however, no experimental support for this hypothesis was given. Carbonyl O-sulfides have also been implicated as intermediates from the photolysis of oxathiiranes. The authors report evidence for the formation of 4 during the decomposition of 1 and that elemental sulfur (S/sub 8/) is formed during the