- Palladium(ii)-catalysed ortho-arylation of N-benzylpiperidines
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PdII-catalysed ortho-arylation of benzylic heterocycles with arylboronic acid pinacol esters (Ar-BPin) via directed C-H bond activation to generate the desired biaryl products is reported. This methodology is efficient and applicable to a wide range of functionalised Ar-BPin and benzylic heterocycles, allowing the direct synthesis of important biaryl motifs in modest to good yield. This journal is
- Tan, Peng Wen,Haughey, Maxwell,Dixon, Darren J.
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supporting information
p. 4406 - 4409
(2015/03/18)
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- Reusable supported ruthenium catalysts for the alkylation of amines by using primary alcohols
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Efficient and recyclable ruthenium catalysts were synthesized from readily available polystyrene-or silica-supported phosphine ligands. Catalysts bound to the polymer support through an ether linkage showed good to excellent activity towards the N-alkylation of primary and secondary amines to afford the alkylated products in 62-99 % yield at 120-140°C. The supported phosphine ligand/ruthenium ratio was found to be crucial for higher catalytic activity and lower ruthenium leaching. The continuous flow N-alkylation of amines was demonstrated by using the supported catalyst in a column reactor. By adopting the hydrogen-borrowing strategy, the synthesis of the anti-Parkinson agent Piribedil was established in 98 % yield at 140°C. Support group steals the show: An efficient Ru-based heterogeneous catalyst from readily available supported phosphine ligands is developed. The nature of the linkage and the extent of ruthenium incorporation are crucial in determining the catalytic activity. The catalyst can be recycled and used under continuous flow in a packed-bed reactor. The alkylation of cyclic amines is achieved in excellent yield at moderate temperatures in the absence of any external base.
- Peishan, Siah,Dang, Tuan Thanh,Seayad, Abdul Majeed,Ramalingam, Balamurugan
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p. 808 - 814
(2014/03/21)
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- A convenient and general reduction of amides to amines with low-valent titanium
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Low-valent titanium readily prepared in situ from TiCl4 and Mg powder in THF is found to be an active agent for the reduction of amides which were previously considered to be inert towards low-valent titanium. The reaction proceeds under very mild conditions, and is applicable to all types of amides, primary, secondary and tertiary, to produce the corresponding amines in good to excellent yields. This new finding provides a practical, convenient and general method for the important transformation of amides to amines. A plausible reaction mechanism is proposed.
- Zhang, Tongxin,Zhang, Yan,Zhang, Weixi,Luo, Meiming
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supporting information
p. 2775 - 2780
(2014/03/21)
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- MANNICH REACTIONS OF ARYLTRIALKYLSTANNANES IN APROTIC SOLVENTS
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Aryltributyl- and aryltrimethyl-stannanes react with a range of N,N-dialkylmethylene-imonium salts to afford N,N-dialkylaminomethyl derivatives in good yields.The method can be used to obtain regioisomers that are not available using classical procedures. "In situ" reactions can also be carried out using alkoxydialkylaminomethanes (aminol ethers) and bis(dialkylamino)methanes (aminals) together with chlorotrimethyl- and trichloromethyl-silanes as the source of the electrophile.However, the "in situ" reactions do not afford good yields in the majority of cases, as a result of the inhibition of imonium salt formation by trialkylchlorostannane.
- Cooper, Mark S.,Fairhurst, Robin A.,Heaney, Harry,Papageorgiou, George,Wilkins, Robert F.
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p. 1155 - 1166
(2007/10/02)
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- MANNICH REACTIONS OF ARYL-TRIALKYLSTANNANES USING PREFORMED DIALKYL-METHYLENEIMINIUM SALTS
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Dialkyl-methyleneiminium salts react with aryl-tributyl- and aryl-trimethylstannanes to afford the corresponding N,N-dialkylaminomethyl- derivatives in good yields.The method can be used to obtain isomers that are not obtained by classical procedures.
- Cooper, Mark S.,Heaney Harry
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p. 5011 - 5014
(2007/10/02)
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