α-Aroylidineketene dithioacetal chemistry: CuI catalyzed synthesis of 2-styryl benzimidazoles enroute to regioselective hydrothiolation
摘要:
Reactivity of alpha-aroylidineketene dithioacetals 2 was investigated to synthesize novel 2-styrylbenzimidazole derivatives 4 and their hydrothiolated product 2-(2-(methylthio)-2-arylethyl)-1H-benzoidlimidazoles 5 has been reported. Compounds 4 and 5 were synthesized by cyclocondensation of alpha-aroylidineketene dithioacetals 2 and o-phenylene diamine (OPD) 3 in the presence and absence of copper catalyst respectively. Regioselective one-pot tandem hydrothiolation of olefin functionality in 4 was achieved under AcOH conditions. (C) 2015 Elsevier Ltd. All rights reserved.
Polarized Ketene Dithioacetals; 55:<sup>1</sup>Synthesis of Novel 5-Aryl-2-methylthio-4<i>H</i>-pyran-4-ones from Cinnamoylketene Dithioacetals
作者:B. Deb、C. V. Asokan、H. Ila、H. Junjappa
DOI:10.1055/s-1987-28112
日期:——
A novel method for the synthesis of 5-aryl-2-methylthio-4H-pyran-4-ones 4a-h has been developed from the corresponding cinnamoylketene dithioacetals 1a-h in three successive steps. In the first step, 1a-h were oxidized with alkaline hydrogen peroxide to give the corresponding (β-aryl-,α,β-epoxypropanoyl)ketene dithioacetals 2a-h in 78-89% overall yields. In the second step the epoxyketones 2a-h were subjected to rearrangement in the presence of ether-boron trifluoride complex to give the corresponding (α-formyl-α-phenylacetyl)ketene dithioacetals 3a-h, which were then cyclized in the third step by refluxing in acetic acid/ethanol to afford the title compounds in good yields.
Synthesis of chiral α-carbonyl-δ-nitro-ketenedithioacetals via l-proline-catalyzed Michael addition reaction
作者:Mathiyazhagan Arun Divakar、Sivakumar Shanmugam
DOI:10.1007/s11164-017-3025-1
日期:2017.12
Abstract Regioselective synthesis of 1,1-bis(methylthio)-6-nitro-5-arylhex-1-en-3-one has been achieved from α-alkenoylketene dithioacetals with nitromethane using l-proline catalyst viaMichaeladdition. The synthesized compounds 3a–j were well characterised by NMR and mass spectral techniques. One of the structures was confirmed by single crystal XRD. The enantioselectivity and its specific rotation
Singh, L. W.; Ila, H.; Junjappa, H., Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1987, vol. 26, # 1-12, p. 607 - 610
作者:Singh, L. W.、Ila, H.、Junjappa, H.
DOI:——
日期:——
Reformatskii reaction on .alpha.-oxo ketene dithioacetals: synthesis of substituted and fused ethyl 2-hydroxy-6-(methylthio)benzoates, 6-(methylthio)pyran-2-ones, and 6-(methylthio)-2(1H)pyridone derivatives