TY - JOUR A1 - Schmidt, Bernd A1 - Elizarov, Nelli A1 - Riemer, Nastja A1 - Hölter, Frank T1 - Acetamidoarenediazonium Salts: Opportunities for Multiple Arene Functionalization JF - European journal of organic chemistry N2 - Unlike their ortho counterparts, meta- and para-acetamidoanilines can be converted into the corresponding acetamidoarenediazonium salts. These offer various opportunities for multiple Pd-catalyzed arene functionalization reactions, such as Matsuda-Heck-, Suzuki-Miyaura- or Fujiwara-Moritani couplings. KW - Arenes KW - Amides KW - C-C coupling KW - Cross-coupling KW - Palladium Y1 - 2015 U6 - https://doi.org/10.1002/ejoc.201500795 SN - 1434-193X SN - 1099-0690 IS - 26 SP - 5826 EP - 5841 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Schmidt, Bernd A1 - Riemer, Martin A1 - Schilde, Uwe T1 - Tandem Claisen Rearrangement/6-endo Cyclization Approach to Allylated and Prenylated Chromones JF - European journal of organic chemistry N2 - Allyl, dimethylallyl and prenyl ethers derived from o-acyl-phenols reacted upon microwave irradiation to form C-allylated or -prenylated chromone derivatives, depending on the substitution pattern of the arene and the allyl substituent. The reaction proceeds through a tandem Claisen rearrangement and 6-endo-trig or 6-endo-dig cyclization sequence. For prenyl ethers, the tandem sequence can be extended by a Cope rearrangement to furnish 6-prenylchromones. The method is potentially useful for the synthesis of natural products and drugs. KW - Allylic compounds KW - Arenes KW - Oxygen heterocycles KW - Microwave chemistry KW - Rearrangement KW - Michael addition Y1 - 2015 U6 - https://doi.org/10.1002/ejoc.201501151 SN - 1434-193X SN - 1099-0690 IS - 34 SP - 7602 EP - 7611 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Schmidt, Bernd A1 - Schultze, Christiane T1 - A one-pot synthesis of pyranocoumarins through microwave-promoted propargyl claisen rearrangement/wittig olefination JF - European journal of organic chemistry N2 - The reaction between propargyl ethers of hydroxybenzaldehydes and the ylide ethyl (triphenylphosphoranylidene)acetate was carried out under microwave irradiation to regioselectively afford angular pyranocoumarins. The chromene and coumarin heterocyclic scaffolds were simultaneously formed in the same synthetic step without changing the reaction conditions. The natural products seselin, braylin, and dipetalolactone were among the products synthesized by this method. KW - Domino reactions KW - Alkynes KW - Arenes KW - Oxygen heterocycles KW - Microwave chemistry KW - Rearrangement Y1 - 2017 SN - 1434-193X SN - 1099-0690 VL - 2018 IS - 2 SP - 223 EP - 227 PB - Wiley-VCH Verl. CY - Weinheim ER - TY - JOUR A1 - Sand, Patrick A1 - Schmidt, Bernd T1 - Ruthenium-catalyzed sulfoalkenylation of acetanilides and dual-use of the catalyst directing group JF - European journal of organic chemistry N2 - In contrast to vinylsulfonates and vinylsulfones, vinylsulfonamides are unreactive in Pd-catalyzed oxidative Heck-coupling reactions with acetanilides. This limitation has been resolved by using a C-H-activation protocol based on Ru-Cu-Ag-catalysis. Overall, the Ru-Cu-Ag-catalyzed conditions turned out to be more reliable and showed better reproducibility than the Pd-catalyzed C-H-activation. The coupling products thus obtained are functionalized styrenyl sulfones and -sulfonamides which can be used as starting materials for the synthesis of sulfonyl pyrroles and sulfonyl pyrrolo[2,3-c]quinolines. KW - Arenes KW - C-H activation KW - Heterocycles KW - Ruthenium KW - Sulfonamides Y1 - 2021 U6 - https://doi.org/10.1002/ejoc.202101216 SN - 1434-193X SN - 1099-0690 VL - 2021 IS - 40 SP - 5497 EP - 5506 PB - Wiley-VCH CY - Weinheim ER -