The Experts below are selected from a list of 183 Experts worldwide ranked by ideXlab platform
Qun Liu - One of the best experts on this subject based on the ideXlab platform.
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Hydrobromic Acid catalyzed friedel crafts type reactions of naphthols
RSC Advances, 2014Co-Authors: Hongjuan Yuan, Mang Wang, Yingjie Liu, Qun LiuAbstract:Catalyzed by 10 mol% of Hydrobromic Acid, hydroxyalkylation and allylation-iodocyclization of naphthols proceeded smoothly under mild conditions. In contrast, other Bronsted Acids tested, including HCl, HI, HBF4, HPF6, TFA, PTSA, H2SO4, TfOH etc., are almost ineffective under identical conditions or require harsh reaction conditions.
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Hydrobromic Acid-catalyzed Friedel–Crafts type reactions of naphthols
RSC Adv., 2014Co-Authors: Hongjuan Yuan, Mang Wang, Yingjie Liu, Qun LiuAbstract:Catalyzed by 10 mol% of Hydrobromic Acid, hydroxyalkylation and allylation-iodocyclization of naphthols proceeded smoothly under mild conditions. In contrast, other Bronsted Acids tested, including HCl, HI, HBF4, HPF6, TFA, PTSA, H2SO4, TfOH etc., are almost ineffective under identical conditions or require harsh reaction conditions.
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Unexpected Hydrobromic Acid‐Catalyzed C ? C Bond‐Forming Reactions and Facile Synthesis of Coumarins and Benzofurans Based on Ketene Dithioacetals
Chemistry (Weinheim an der Bergstrasse Germany), 2010Co-Authors: Hongjuan Yuan, Mang Wang, Jun Liu, Yingjie Liu, Lili Wang, Qun LiuAbstract:Hydrobromic Acid was found to be a unique catalyst in CC bond-forming reactions with ketene dithioacetals. Distinctly different from other Acids (including Lewis and Bronsted Acids), the remarkable catalytic performance of Hydrobromic Acid in catalytic amounts was observed in the “Acid”-catalyzed reactions of readily available functionalized ketene dithioacetals 1 with various electrophiles. Under the catalysis of 0.1 equivalents of Hydrobromic Acid, the reaction of 1 with carbonyl compounds 2 a–l gave polyfunctionalized penta-1,4-dienes 3 or conjugated dienes 4 in good to excellent yields. The reaction tolerated a broad range of substituents on both the ketene dithioacetals 1 and the carbonyl compounds 2. Application of this efficient CC bond-forming method generated coumarins 5 and benzofurans 7 under mild, metal-free conditions by Hydrobromic Acid-catalyzed reactions of 1 with salicylaldehydes 2 m–o and p-quinones 6 a–d, respectively. A new reactive species, a sulfur-stabilized carbonium ylide, formed depending on the nature of the counterion, and this was proposed as the key intermediate in the unique catalysis of Hydrobromic Acid.
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Unexpected Hydrobromic Acid-catalyzed C-C bond-forming reactions and facile synthesis of coumarins and benzofurans based on ketene dithioacetals
Chemistry - A European Journal, 2010Co-Authors: Hongjuan Yuan, Yi-qun Liu, Likui Wang, Mang Wang, Jun Liu, Qun LiuAbstract:Hydrobromic Acid was found to be a unique catalyst in C-C bond-forming reactions with ketene dithioacetals. Distinctly different from other Acids (including Lewis and Brønsted Acids), the remarkable catalytic performance of Hydrobromic Acid in catalytic amounts was observed in the "Acid"-catalyzed reactions of readily available functionalized ketene dithioacetals 1 with various electrophiles. Under the catalysis of 0.1 equivalents of Hydrobromic Acid, the reaction of 1 with carbonyl compounds 2a-l gave polyfunctionalized penta-1,4-dienes 3 or conjugated dienes 4 in good to excellent yields. The reaction tolerated a broad range of substituents on both the ketene dithioacetals 1 and the carbonyl compounds 2. Application of this efficient C-C bond-forming method generated coumarins 5 and benzofurans 7 under mild, metal-free conditions by Hydrobromic Acid-catalyzed reactions of 1 with salicylaldehydes 2m-o and p-quinones 6a-d, respectively. A new reactive species, a sulfur-stabilized carbonium ylide, formed depending on the nature of the counterion, and this was proposed as the key intermediate in the unique catalysis of Hydrobromic Acid.
Daniel A. Dickman - One of the best experts on this subject based on the ideXlab platform.
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Oxidative cleavage of aryl or alkyl tert-butyl sulfides with dimethyl sulfoxide/Hydrobromic Acid to form symmetrical aryl or alkyl disulfides
Synthesis, 1993Co-Authors: Daniel A. Dickman, Sanjay Chemburkar, Donald B. Konopacki, E. Michael ElisseouAbstract:The use of dimethyl sulfoxide and Hydrobromic Acid as a reagent to oxidatively cleave (tert-butylthio)benzaldehydes, aryl or alkyl tert-butyl sulfides to their corresponding symmetrical disulfides is discussed. A brief mechanistic rationale is given based upon several control experiments
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oxidative cleavage of aryl or alkyl tert butyl sulfides with dimethyl sulfoxide Hydrobromic Acid to form symmetrical aryl or alkyl disulfides
Synthesis, 1993Co-Authors: Daniel A. Dickman, Sanjay Chemburkar, Donald B. Konopacki, Michael E ElisseouAbstract:The use of dimethyl sulfoxide and Hydrobromic Acid as a reagent to oxidatively cleave (tert-butylthio)benzaldehydes, aryl or alkyl tert-butyl sulfides to their corresponding symmetrical disulfides is discussed. A brief mechanistic rationale is given based upon several control experiments
Hongjuan Yuan - One of the best experts on this subject based on the ideXlab platform.
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Hydrobromic Acid catalyzed friedel crafts type reactions of naphthols
RSC Advances, 2014Co-Authors: Hongjuan Yuan, Mang Wang, Yingjie Liu, Qun LiuAbstract:Catalyzed by 10 mol% of Hydrobromic Acid, hydroxyalkylation and allylation-iodocyclization of naphthols proceeded smoothly under mild conditions. In contrast, other Bronsted Acids tested, including HCl, HI, HBF4, HPF6, TFA, PTSA, H2SO4, TfOH etc., are almost ineffective under identical conditions or require harsh reaction conditions.
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Hydrobromic Acid-catalyzed Friedel–Crafts type reactions of naphthols
RSC Adv., 2014Co-Authors: Hongjuan Yuan, Mang Wang, Yingjie Liu, Qun LiuAbstract:Catalyzed by 10 mol% of Hydrobromic Acid, hydroxyalkylation and allylation-iodocyclization of naphthols proceeded smoothly under mild conditions. In contrast, other Bronsted Acids tested, including HCl, HI, HBF4, HPF6, TFA, PTSA, H2SO4, TfOH etc., are almost ineffective under identical conditions or require harsh reaction conditions.
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Unexpected Hydrobromic Acid‐Catalyzed C ? C Bond‐Forming Reactions and Facile Synthesis of Coumarins and Benzofurans Based on Ketene Dithioacetals
Chemistry (Weinheim an der Bergstrasse Germany), 2010Co-Authors: Hongjuan Yuan, Mang Wang, Jun Liu, Yingjie Liu, Lili Wang, Qun LiuAbstract:Hydrobromic Acid was found to be a unique catalyst in CC bond-forming reactions with ketene dithioacetals. Distinctly different from other Acids (including Lewis and Bronsted Acids), the remarkable catalytic performance of Hydrobromic Acid in catalytic amounts was observed in the “Acid”-catalyzed reactions of readily available functionalized ketene dithioacetals 1 with various electrophiles. Under the catalysis of 0.1 equivalents of Hydrobromic Acid, the reaction of 1 with carbonyl compounds 2 a–l gave polyfunctionalized penta-1,4-dienes 3 or conjugated dienes 4 in good to excellent yields. The reaction tolerated a broad range of substituents on both the ketene dithioacetals 1 and the carbonyl compounds 2. Application of this efficient CC bond-forming method generated coumarins 5 and benzofurans 7 under mild, metal-free conditions by Hydrobromic Acid-catalyzed reactions of 1 with salicylaldehydes 2 m–o and p-quinones 6 a–d, respectively. A new reactive species, a sulfur-stabilized carbonium ylide, formed depending on the nature of the counterion, and this was proposed as the key intermediate in the unique catalysis of Hydrobromic Acid.
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Unexpected Hydrobromic Acid-catalyzed C-C bond-forming reactions and facile synthesis of coumarins and benzofurans based on ketene dithioacetals
Chemistry - A European Journal, 2010Co-Authors: Hongjuan Yuan, Yi-qun Liu, Likui Wang, Mang Wang, Jun Liu, Qun LiuAbstract:Hydrobromic Acid was found to be a unique catalyst in C-C bond-forming reactions with ketene dithioacetals. Distinctly different from other Acids (including Lewis and Brønsted Acids), the remarkable catalytic performance of Hydrobromic Acid in catalytic amounts was observed in the "Acid"-catalyzed reactions of readily available functionalized ketene dithioacetals 1 with various electrophiles. Under the catalysis of 0.1 equivalents of Hydrobromic Acid, the reaction of 1 with carbonyl compounds 2a-l gave polyfunctionalized penta-1,4-dienes 3 or conjugated dienes 4 in good to excellent yields. The reaction tolerated a broad range of substituents on both the ketene dithioacetals 1 and the carbonyl compounds 2. Application of this efficient C-C bond-forming method generated coumarins 5 and benzofurans 7 under mild, metal-free conditions by Hydrobromic Acid-catalyzed reactions of 1 with salicylaldehydes 2m-o and p-quinones 6a-d, respectively. A new reactive species, a sulfur-stabilized carbonium ylide, formed depending on the nature of the counterion, and this was proposed as the key intermediate in the unique catalysis of Hydrobromic Acid.
Michael E Elisseou - One of the best experts on this subject based on the ideXlab platform.
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oxidative cleavage of aryl or alkyl tert butyl sulfides with dimethyl sulfoxide Hydrobromic Acid to form symmetrical aryl or alkyl disulfides
Synthesis, 1993Co-Authors: Daniel A. Dickman, Sanjay Chemburkar, Donald B. Konopacki, Michael E ElisseouAbstract:The use of dimethyl sulfoxide and Hydrobromic Acid as a reagent to oxidatively cleave (tert-butylthio)benzaldehydes, aryl or alkyl tert-butyl sulfides to their corresponding symmetrical disulfides is discussed. A brief mechanistic rationale is given based upon several control experiments
E. Michael Elisseou - One of the best experts on this subject based on the ideXlab platform.
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Oxidative cleavage of aryl or alkyl tert-butyl sulfides with dimethyl sulfoxide/Hydrobromic Acid to form symmetrical aryl or alkyl disulfides
Synthesis, 1993Co-Authors: Daniel A. Dickman, Sanjay Chemburkar, Donald B. Konopacki, E. Michael ElisseouAbstract:The use of dimethyl sulfoxide and Hydrobromic Acid as a reagent to oxidatively cleave (tert-butylthio)benzaldehydes, aryl or alkyl tert-butyl sulfides to their corresponding symmetrical disulfides is discussed. A brief mechanistic rationale is given based upon several control experiments