نتایج جستجو برای: regioselectivity

تعداد نتایج: 1520  

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2011
Philipp Wucher Lucia Caporaso Philipp Roesle Francesco Ragone Luigi Cavallo Stefan Mecking Inigo Göttker-Schnetmann

In modern methods for the preparation of small molecules and polymers, the insertion of substrate carbon-carbon double bonds into metal-carbon bonds is a fundamental step of paramount importance. This issue is illustrated by Mizoroki-Heck coupling as the most prominent example in organic synthesis and also by catalytic insertion polymerization. For unsymmetric substrates H(2)C = CHX the regiose...

Journal: :Chemical communications 2012
Hongli Liu Biaolin Yin Zhiqiang Gao Yingwei Li Huanfeng Jiang

A novel heterogeneous catalysis system using metal-organic frameworks as catalyst demonstrated excellent chemo- and regioselectivity for the direct arylation of unactivated arenes with aryl iodides/bromides without the assistance of any transition metals.

Journal: :Chemical communications 2004
Masao Aoki Motomu Kaneko Sawa Izumi Kazutoshi Ukai Nobuharu Iwasawa

Novel bidentate amidines were designed and synthesized as easily available electron-donating N-ligands for Ni0-mediated coupling of carbon dioxide with alkynes or allenes, and high regioselectivity was achieved even for the carboxylation of aryl substituted internal alkynes.

Journal: :Chemical communications 2009
Jianhui Huang Simon J F Macdonald Joseph P A Harrity

The [3 + 2] cycloaddition of alkynylboronates and azides provides a direct route to novel triazole boronic esters, the regioselectivity of this process and functionalisation of the heterocycle products is described.

Journal: :Organic & biomolecular chemistry 2011
Tianmin Niu Lehao Huang Tianxing Wu Yuhong Zhang

An efficient iron-promoted alkylation of indoles with enamides has been accomplished under mild reaction conditions. The reaction proceeded with remarkable regioselectivity leading exclusively to substitution by indoles at α-position of enamides.

Journal: :Chemical communications 2013
Tina M Konrad Jamie T Durrani Christopher J Cobley Matthew L Clarke

Using a family of novel mononuclear and dinuclear palladium complexes of phanephos ligands, the simultaneous control of regioselectivity and enantioselectivity in the hydroxycarbonylation and alkoxycarbonylation of styrene derivatives has been realised for the first time.

Journal: :Chemical communications 2015
Vasudeva Rao Gandi Yixin Lu

The first phosphine catalysed Michael addition of arylcyanoacetates to allenoates has been developed, and the β-selective products with a quaternary center were obtained in excellent yields. This unusual regioselectivity may open new opportunities to access interesting molecular structures.

Journal: :Synthesis 2023

Abstract Anilines selectively arylated at their ortho, meta or para positions are useful building blocks in synthesis and have found applications many areas. The most straightforward method for relies on the direct arylation of a C(sp2)–H bond anilines, an attractive strategy avoiding prefunctionalization starting anilines provided that such arylations proceed with high levels regioselectivity....

Journal: :Angewandte Chemie 2013
Tanguy Saget Nicolai Cramer

Tada! Highly functionalized chiral dibenzazepinones are obtained by a mild palladium(0)-catalyzed enantioselective C-H arylation with excellent selectivities by using simple taddol phosphoramidite ligands. The amide tether allows exclusive regioselectivity through a rare eight-membered palladacycle intermediate.

Journal: :Dalton transactions 2008
Jamie J R Frew Matthew L Clarke Ulrich Mayer Hendrik Van Rensburg Robert P Tooze

Some new bulky fluorinated diphosphines have been prepared and converted to palladium dichloride complexes that have been found to give increased regioselectivity and activity over other Pd-diphosphine systems when used as catalysts for hydroxycarbonylation of styrene.

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