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An efficient, reusable and stable binaphthyl stabilized Pd‐nanoparticles (Pd‐BNP) catalyzed the direct ortho‐C−H hydroxylation of acetophenone oxime ethers under neutral and phosphine ligand‐free condition has been developed. A readily available, economic, safe and greener oxidant oxone has been used in this direct ortho‐hydroxylation. The scope of the reaction has been studied with various acetophenone oxime ethers including electron rich to electron deficient system and the reaction afforded only mono hydroxylated products in a highly regioselective manner. Several control experiment results confirmed that the oxone is the hydroxyl source. The Pd‐BNP catalyst has been reused up to five times. The heterogeneous test confirmed that the reaction is catalyzed by the heterogeneous Pd‐BNP catalyst. [ABSTRACT FROM AUTHOR]

A highly efficient and atom-economical route for the synthesis of substituted β-arylethyl ketones was developed by using cheap phosphomolybdic acid (H3PMo12O40) as catalyst and non-volatile propylene carbonate (PC) as green solvent via the carbohydroxylation of terminal alkynes with benzylic alcohols under mild conditions. Various functional groups on the benzylic alcohols and terminal alkynes were tolerated, giving the corresponding substituted β-arylethyl ketones as products in good to excellent yields (up to 95%). It is worth noting that a turnover number (TON) of up to 520 was achieved in the protocol. The mechanism investigation showed that PC might stabilize the heteropoly anion and the carbocation intermediate thus facilitating the carbohydroxylation reaction. [ABSTRACT FROM AUTHOR]

We herein report the first total synthesis of the dibenzocycloheptanoide (±)-dihydroisosubamol. The key step includes a recently developed gold-catalysed hydroarylation reaction for the construction of the dibenzocycloheptene motif. Additional steps are a Suzuki-Miyaura cross coupling, a palladium-catalysed hydroxylation and an allylic oxidation. To access the saturated seven-membered ring system an iridium-catalysed hydrogenation proved to be successful. [ABSTRACT FROM AUTHOR]

Palladium-catalyzed oxidative homocoupling and hydroxylation of 3-arylbenzo[ d]isoxazoles have been developed via direct C( sp2)−H bond activation using benzoisoxazoles as a new directing group. The protocols offer a divergent approach to functionalized, synthetically useful benzoisoxazoles in good yields. Critically, 1-iodo-4-methoxybenzene functions as an oxidant to mediate the dehydrogenative homocoupling and minimize the cross-coupling. A dual-core dimeric palladacycle intermediate is confirmed by X-ray crystallography, and serves as an active catalytic species in the catalytic cycles. [ABSTRACT FROM AUTHOR]

A natural quinine-catalyzed, efficient and practical asymmetric α-hydroxylation of 4-substituted pyrazolones has been developed, delivering a broad spectrum of pyrazolones bearing an oxygen-attached carbon stereocenter at C-4 in high yields and excellent enantioselectivities. The broad substrate scope, ready availability of the catalyst, ease of operation, and valuable transformation of the product highlight the practical utility of this process. [ABSTRACT FROM AUTHOR]