Rongalite: A Useful Green Reagent in Organic Synthesis

Recent Developments in the Chemistry of Thiourea Oxides

“…There is only one relatively old review devoted to the more notable sulfur-containing reducing agents with CÀS and SÀS bonds: dithionite, rongalite, and thiourea dioxide. [2] Since then, at least two reviews on related thiourea dioxide compounds-sodium dithionite [15] and sodium hydroxymethanesulfinate [16] -have been published, and a review on sulfoxylic acid (the key product of the decomposition of thiourea dioxide) and its anions and ethers is in press. [17] There is, however, no dedicated review on thiourea dioxide and other thiourea oxides.…”

Tris(tetraceno)triquinacenes: Synthesis and Photophysical Properties of Threefold Linearly Extended Tribenzotriquinacenes

“…Although the intermediacy of 6 remains hypothetical, indeed, thermolysis of tris-sulfone 5 gave rise to threefold Diels-Alder reactions with quinones (Scheme 2). Thus, heating compound 5 in 1,2,4-trichlorobenzene in the presence of an excess of para-benzoquinone gave a product mixture which, after treatment with activated manganese dioxide in 1,4-dioxane under reflux, [31] furnished the tris-1,4-anthraquinone 7 in moderate yield. Likewise, thermolysis of 5 in the presence of 1,4-naphthoquinone under similar conditions gave a mixture of partially and fully aromatized products, which were subjected to chromatography before aromatization.…”

Design and Synthesis of Polycycles, Heterocycles, and Macrocycles via Strategic Utilization of Ring‐Closing Metathesis

“…We successfully applied RCM strategy for the synthesis of symmetrical sulfone derivatives . To this end, the terminal‐olefin‐containing symmetrical sulfones 102 a – b were produced with various alkenyl bromides of varying chain length with an excess amount of rongalite in the presence of K 2 CO 3 and tetrabutylammonium bromide (TBAB). When the alkenyl sulfone derivatives (where n=1 and 2) 102 a and 102 b were subjected to RCM in the presence of G‐I catalyst in refluxing CH 2 Cl 2 the cyclic sulfones 103 a – b were produced in 97 % yield.…”

“…A simple method to synthesize various cyclophanes was conceived by employing the Claisen rearrangement (CR) in sequence with RCM. [14] The key precursor 31 was assembled from a readily available 2,6-pyridinedicarbonitrile (28). To this end, O-allyl-p-bromophenol (27) obtained from 4bromophenol, was used in the preparation of Grignard reagent.…”