Catalyst-Controlled Site-Selective N-H and C3-Arylation of Carba-zole via Carbene Transfer Reactions

2021 ◽  
Author(s):  
Sourav Sekhar Bera ◽  
Srishti Ballabh Bahukhandi ◽  
Claire Empel ◽  
Rene M Koenigs

A site-selective direct arylation reaction of carbazole and other N-heterocycles with diazo-naphthalen-2(1H)-ones has been developed. While Au(I)-NHC catalysts lead to selective C3-arylation, palladium acetate allows for selective N-H arylation, displaying...

1996 ◽  
Vol 451 ◽  
Author(s):  
D. Lincot ◽  
M. J. Furlong ◽  
M. Froment ◽  
R. Cortes ◽  
M. C. Bernard

ABSTRACTChalcogenide semiconductors have been deposited epitaxially from aqueous solutions either chemically or electrochemically at growth rates of up to 0.7 μmhr−1. After recalling the basic principles of these deposition processes, results are presented concerning chemically deposited CdS on InP, GaP and CuInSe2 substrates, electrodeposited CdTe on InP, and CdSAnP heterostructures. Characterisation of these structures by RHEED, TEM, HRTEM, and glazing angle X ray diffraction allows to analyse the effects of substrate orientation, polarity, lattice match plus the influence of temperature on epitaxial growth. These results are discussed in terms of self organisation and a site selective growth mechanisms due to the free enegy of formation of each compound.


2020 ◽  
Vol 49 (6) ◽  
pp. 689-692
Author(s):  
Keisuke Ueno ◽  
Yuji Nishii ◽  
Masahiro Miura

2021 ◽  
Vol 6 (43) ◽  
pp. 12032-12035
Author(s):  
Jinjing Qin ◽  
Zhenhua Li ◽  
Yingyan Cao ◽  
Yuanyuan Xie ◽  
Weike Su
Keyword(s):  
A Site ◽  

2021 ◽  
Author(s):  
Viktoriia Postupalenko ◽  
Léo Marx ◽  
David Viertl ◽  
Natalia Gasilova ◽  
Mathilde Plantin ◽  
...  

1999 ◽  
Vol 28 (5) ◽  
pp. 315-322 ◽  
Author(s):  
Shiuh-Tzung Liu ◽  
K. Rajender Reddy

2009 ◽  
Vol 49 (1) ◽  
pp. 144-147 ◽  
Author(s):  
Jun Terao ◽  
Masahiro Tomita ◽  
Surya Prakash Singh ◽  
Nobuaki Kambe

2020 ◽  
Author(s):  
Sripati Jana ◽  
Claire Empel ◽  
Chao Pei ◽  
Polina Aseeva ◽  
Thanh Vinh Nguyen ◽  
...  

<p>The C-H functionalization reaction of N-heterocycles with unprotected N-H group is one of the most step-economic strategies to introduce functional groups without the need of installation and removal of protecting groups. Despite recent significant advances in C-H functionalization chemistry, this strategy remains unsatisfactorily developed. In this report, we disclose a simple and straightforward protocol to allow for the selective C-H functionalization of unprotected double benzannellated N-heterocycles via gold catalyzed carbene transfer reactions (29 examples, up to 86% yield). The scope of the reaction can also be expanded to the corresponding protected heterocycles (37 examples, up to 98% yield), further demonstrating the generality of this method. Mechanistic studies by DFT calculations underpin the importance of the gold catalyst and reveal that the selectivity of this reaction is driven by trace amounts of water present in the reaction mixture.</p>


2018 ◽  
Author(s):  
Martin A. Fascione ◽  
Richard J. Spears ◽  
Robin L. Brabham ◽  
Darshita Budhadev ◽  
Tessa Keenan ◽  
...  

The bioconjugation of proteins with small molecules has proved an invaluable strategy for probing and perturbing dynamic biological mechanisms. The general use of chemical methods for the functionalisation of proteins remains limited however by the frequent requirement for complicated reaction partners to be present in large excess, and harsh reaction conditions which are incompatible with many protein scaffolds. Herein we describe a site-selective organocatalyst-mediated protein aldol ligation (OPAL) that affords stable carbon-carbon linked bioconjugates at neutral pH under biocompatible conditions. OPAL enables rapid chemical modification of proteins within an hour using simple aldehyde probes in minimal excess, and is utilised here in the selective affinity tagging of proteins in cell lysate. Furthermore we demonstrate that the b-hydroxy aldehyde product of the OPAL can be functionalised a second time at neutral pH in a subsequent organocatalyst-mediated oxime ligation. This tandem strategy is showcased in the ‘chemical mimicry’ of a previously inaccessible natural dual post-translationally modified protein integral to the pathogenesis of the neglected tropical disease Leishmaniasis. <br>


2021 ◽  
Vol MA2021-01 (42) ◽  
pp. 1727-1727
Author(s):  
Nai-Hua Yeh ◽  
Albert Huang ◽  
Kevin D Moeller
Keyword(s):  
A Site ◽  

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