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Direct Arylation. Speaker: Chien -An Chen Teacher: Guey -Sheng Liou. Important bi(hetero)aryls. Direct Arylation V.S. Traditional Cross-Coupling. Define of direct arylation : Through cleavage of C-H bond. Advantage of direct arylation : Without metallic halides by-product
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Direct Arylation Speaker: Chien-An Chen Teacher: Guey-Sheng Liou
Direct Arylation V.S. Traditional Cross-Coupling Define of direct arylation: Through cleavage of C-H bond Advantage of direct arylation: Without metallic halides by-product →good for enviorment Reduce the synthetic operations →economical
Direct Arylation on LBG polymer UllrichScherf et al. , ACS Macro Lett. 2012, 1, 465−468
Direct Arylation on LBG polymer TakakiKanbara et al. , ACS Macro Lett. 2012, 1, 67−70
Direct Arylation on LBG polymer • Disadvantage: The critical factor of direct arylation polymerization is regioselectivity. Example: Solution method: Use protecting group, methyl, to protect 3-position of thiophene. Example: The two hydrogen atoms are also reactive Cross-linked polymer
Conclusion • Until very recently, the majority of catalytic direct arylationshave been accomplished with palladium, rhodium, or ruthenium catalysts. However, less-expensive copper, iron, and nickel compounds have been shown. • The use of atom-economical terminal oxidants and achieving regioselectivity in intermolecular arylations remain significant challenges.