1610616-75-5Relevant academic research and scientific papers
Enantioselective Construction of Tertiary C-O Bond via Allylic Substitution of Vinylethylene Carbonates with Water and Alcohols
Khan, Ajmal,Khan, Sardaraz,Khan, Ijaz,Zhao, Can,Mao, Yuxue,Chen, Yan,Zhang, Yong Jian
, p. 10733 - 10741 (2017)
An efficient method for the enantioselective construction of tertiary C-O bond via asymmetric allylic substitution of racemic vinylethylene carbonates with water and alcohols has been developed. Under the cooperative catalysis system of an in situ generated chiral palladium complex and boron reagent in mild conditions, the process allowed rapid access to valuable tertiary alcohols and ethers in high yields with complete regioselectivities and high enantioselectivities. This protocol represented the first example of direct enantioselective formation of a tertiary C-O bond with water as an oxygen donor. The synthetic utilities of the process have been demonstrated by the elaboration of the products into key intermediates of biologically relevant agents, and chiral tertiary cyclic ethers could also be provided through the sequential reactions of the allylic etherification and ring-closing metathesis.
Preparation method and application of chiral tertiary alcohol or tertiary ether compound
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Paragraph 0051; 0068-0070, (2017/12/27)
The invention discloses a preparation method and application of a chiral tertiary alcohol or tertiary ether compound. A racemase 4-substituted-4-vinyl-1,3-dioxolan-2-one compound is used as a raw material, and under the catalysis of a palladium coordination compound, which is generated under a palladium source and the coordination action of a chiral ligand, and a boron compound which serve as catalysts, reacts with water or alcohol to prepare the chiral tertiary alcohol or tertiary ether compound. The chiral compound provided by the invention is the multi-functionalized chiral tertiary alcohol or tertiary ether compound, can be used for flexibly and conveniently carrying out functional conversion, is about to be an important chiral molecular building block for preparing a chiral drug and an intermediate. The preparation method provided by the invention comprises asymmetric hydroxylation and etherification reactions co-catalyzed by palladium and boron; the preparation method is high in catalytic activity, high in regioselectivity and enantioselectivity and mild in reaction condition; reactive raw materials are conveniently and easily obtained.
Palladium-catalyzed decarboxylative cycloaddition of vinylethylene carbonates with formaldehyde: Enantioselective construction of tertiary vinylglycols
Khan, Ajmal,Zheng, Renfeng,Kan, Yuhe,Ye, Jiang,Xing, Juxiang,Zhang, Yong Jian
, p. 6439 - 6442 (2014/06/24)
An efficient method for the enantioselective construction of tertiary vinylglycols through a palladium-catalyzed asymmetric decarboxylative cycloaddition of vinylethylene carbonates with formaldehyde was developed. By using a palladium complex generated in situ from [Pd2(dba) 3]·CHCl3 and a phosphoramidite ligand as a catalyst under mild reaction conditions, the process allows conversion of racemic 4-substituted 4-vinyl-1,3-dioxolan-2-ones into the corresponding 1,3-dioxolanes, as methylene acetal protected tertiary vinylglycols, in high yields with good to excellent enantioselectivities.
