- Sulfonamidoquinoline/palladium(II)-dimer complex as a catalyst precursor for palladium-catalyzed γ-Selective and stereospecific allyl-aryl coupling reaction between allylic acetates and arylboronic acids
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On neutral territory: A neutral palladium(II)-dimer catalyst system incorporating anionic sulfonamidoquinoline ligands is effective for the γ-selective and stereospecific allyl-aryl coupling between acyclic (E)-allylic acetates and arylboronic acids. Copy
- Makida, Yusuke,Ohmiya, Hirohisa,Sawamura, Masaya
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supporting information; experimental part
p. 410 - 414
(2011/10/03)
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- Palladium-catalyzed γ-selective and stereospecific allyl-aryl coupling between acyclic allylic esters and arylboronic acids
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Reactions between acyclic (E)-allylic acetates and arylboronic acids in the presence of a palladium catalyst prepared from Pd(OAc)2, phenanthroline (or bipyridine), and AgSbF6 (1:1.2:1) proceeded with excellent γ-selectivity to afford allyl-aryl coupling products with E-configuration. The reactions of α-chiral allylic acetates took place with excellent α-to-γ chirality transfer with syn stereochemistry to give allylated arenes with a stereogenic center at the benzylic position. The reaction tolerated a broad range of functional groups in both the allylic acetates and the arylboronic acids. Furthermore, γ-arylation of cinnamyl alcohol derivatives afforded gem-diarylalkane derivatives containing an unconjugated alkenic substituent. The synthetic utility of this method was demonstrated by its utilization in an efficient synthesis of (+)-sertraline, an antidepressant agent. The observed γ-regioselectivity and E-1,3-syn stereochemistry were rationalized based on a Pd(II) mechanism involving transmetalation between a cationic mono(acyloxo)palladium(II) complex and arylboronic acid, and directed carbopalladation followed by syn-β-acyloxy elimination. The results of stoichiometric reactions of palladium complexes related to possible intermediates were fully consistent with the proposed mechanism.
- Ohmiya, Hirohisa,Makida, Yusuke,Li, Dong,Tanabe, Masahito,Sawamura, Masaya
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supporting information; experimental part
p. 879 - 889
(2010/03/25)
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- Copper-catalyzed substitution reactions of acylal with organomanganese reagents
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A mild method for the copper-catalyzed substitution of aldehyde acylals with organomanganese reagents is reported. This operationally simple C-C bond-forming protocol uses different Cu(I) catalysts. Acylal from trans-cinnamaldehyde furnishes conjugated addition product when reacted with alkyl and aryl organomanganese reagents in presence of 10 mol % of Cu(NCMe) 2 (PPh3)2[BF4] and 2 equivalent of Me3Si-C1 as an accelerator. This reagent can be efficiently used in the substitution of one acetate group of aromatic acylal to form esters in high yield.
- Deshmukh, Madhukar B.,Jadhav, Sunil D.,Kadam, Shashikant V.
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p. 989 - 994
(2008/09/18)
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