- Pd-Catalyzed Heck-Type Reaction: Synthesizing Highly Diastereoselective and Multiple Aryl-Substituted P-Ligands
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In this work, an efficient palladium-catalyzed Heck-type reaction was successfully used to synthesize a wide range of monoaryl-or diaryl-substituted P-ligands with excellent yields and diastereoselectivity (up to 98% yield, dr >20:1). The preliminary mechanistic studies demonstrated that it possibly underwent a cationic Heck reaction that was assisted by silver salt, and it revealed the significant role of P(O)Ar2 for excellent yields and diastereoselectivity.
- Li, Chong,Qiang, Xiao-Yue,Qi, Zhi-Chao,Cao, Bin,Li, Jing-Yu,Yang, Shang-Dong
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p. 7138 - 7142
(2019/09/30)
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- Preparation of cyclopentyl (f) ene-1-boronic acid frequency that ester method
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The invention discloses a method of preparing cyclopenten/cyclohexen-1-yl-boronic acid pinacol ester from methyl 1-cyclopentene/cyclohexene-1-carboxylate by three-step continuous operations. The method includes subjecting the raw material to alkaline hydrolysis to form the corresponding 1-alkylene carboxylic acid; performing addition with bromine; performing elimination and decarboxylation at the same time under the existence of DBU or DMAP to produce 1-bromo cyclopentene/cyclohexene; and allowing the 1-bromo cyclopentene/cyclohexene and methoxyboronic acid pinacol ester to form an ester under the existence of magnesium metal by a one-pot process to obtain the cyclopenten/cyclohexen-1-yl-boronic acid pinacol ester. The method is high in continuity, simple and convenient in operations, free of low-temperature reactions, and capable of obtaining the 1-bromo cyclopentene/cyclohexene intermediate with high purity and meeting market demands. The method adopts one-pot-process of Grignard reaction/esterification, so that the method is more convenient in operations and has less by-products, and the product is easier in rectification purification.
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- Preparation of α-oxygenated ketones by the dioxygenation of alkenyl boronic acids
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Two in two: Dioxygenation of alkenyl boronic acids has been achieved with N-hydroxyphthalimide. The two-step process involves etherification of an alkenyl boronic acid with N-hydroxyphthalimide followed by a [3,3] rearrangement. The dioxygenated product can then be hydrolyzed to form either the corresponding α-hydroxy ketone or the α-benzoyloxy ketone. Copyright
- Patil, Aditi S.,Mo, Dong-Liang,Wang, Heng-Yen,Mueller, Daniel S.,Anderson, Laura L.
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supporting information; experimental part
p. 7799 - 7803
(2012/09/08)
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