Regioselective Cross-Coupling Reactions of Multiple Halogenated Nitrogen-, Oxygen-, and Sulfur-Containing Heterocycles

ChemInform ◽  
2005 ◽  
Vol 36 (25) ◽  
Author(s):  
Sven Schroeter ◽  
Christoph Stock ◽  
Thorsten Bach
2001 ◽  
Vol 79 (11) ◽  
pp. 1632-1654 ◽  
Author(s):  
Richard R Hark ◽  
Diane B Hauze ◽  
Olga Petrovskaia ◽  
Madeleine M Joullié

Ninhydrin is an essential tool in the analysis of amino acids, peptides, and proteins, and the preferred reagent for the detection of latent fingerprints on porous surfaces. The goal of this investigation was to prepare ninhydrin analogs with enhanced chromogenic and fluorogenic properties. Target compounds included structures with extended conjugation and (or) with the presence of sulfur-containing moieties. We have devised general convergent routes for novel heterocyclic and aryl-substituted ninhydrin analogs for use as reagents for amino acid detection.Key words: ninhydrin analogs, synthesis, ketals, Suzuki cross-coupling reactions, Stille cross-coupling reactions.


Synlett ◽  
2019 ◽  
Vol 30 (10) ◽  
pp. 1149-1163 ◽  
Author(s):  
Chunlan Song ◽  
Kun Liu ◽  
Xin Dong ◽  
Chien-Wei Chiang ◽  
Aiwen Lei

With the importance of sulfur-containing organic molecules, developing methodologies toward C–S bond formation is a long-standing goal, and, to date, considerable progress has been made in this area. Recent electrochemical oxidative cross-coupling reactions for C–S bond formation allow the synthesis of sulfur-containing molecules from more effective synthetic routes with high atom economy under mild conditions. In this review, we highlight the vital progress in this novel research arena with an emphasis on the synthetic and mechanistic aspects of the organic electrochemistry reactions.1 Introduction2 Electrochemical Oxidative Sulfonylation for the Formation of C–S Bonds2.1 Applications of Sulfinic Acid Derivatives for the Formation of C–S Bonds2.2 Applications of Sulfonylhydrazide Derivatives for the Formation of C–S Bonds3 Electrochemical Oxidative Thiolation for the Formation of C–S Bonds3.1 Applications of Disulfide Derivatives for the Formation of C–S Bonds3.2 Applications of Thiophenol Derivatives for the Formation of C–S Bonds4 Electrochemical Oxidative Thiocyanation for the Formation of C–S Bonds5 Electrochemical Oxidative Cyclization for the Formation of C–S Bonds6 Conclusion


2016 ◽  
Vol 818 ◽  
pp. 7-14 ◽  
Author(s):  
J.A. Balam-Villarreal ◽  
C.I. Sandoval-Chávez ◽  
F. Ortega-Jiménez ◽  
R.A. Toscano ◽  
M.P. Carreón-Castro ◽  
...  

2020 ◽  
Author(s):  
Baojian Xiong ◽  
Yue Li ◽  
Yin Wei ◽  
Søren Kramer ◽  
Zhong Lian

Cross-coupling between substrates that can be easily derived from phenols is highly attractive due to the abundance and low cost of phenols. Here, we report a dual nickel/palladium-catalyzed reductive cross-coupling between aryl tosylates and aryl triflates; both substrates can be accessed in just one step from readily available phenols. The reaction has a broad functional group tolerance and substrate scope (>60 examples). Furthermore, it displays low sensitivity to steric effects demonstrated by the synthesis of a 2,2’disubstituted biaryl and a fully substituted aryl product. The widespread presence of phenols in natural products and pharmaceuticals allow for straightforward late-stage functionalization, illustrated with examples such as Ezetimibe and tyrosine. NMR spectroscopy and DFT calculations indicate that the nickel catalyst is responsible for activating the aryl triflate, while the palladium catalyst preferentially reacts with the aryl tosylate.


2020 ◽  
Author(s):  
Chet Tyrol ◽  
Nang Yone ◽  
Connor Gallin ◽  
Jeffery Byers

By using an iron-based catalyst, access to enantioenriched 1,1-diarylakanes was enabled through an enantioselective Suzuki-Miyaura crosscoupling reaction. The combination of a chiral cyanobis(oxazoline) ligand framework and 1,3,5-trimethoxybenzene additive were essential to afford high yields and enantioselectivities in cross-coupling reactions between unactivated aryl boronic esters and a variety of benzylic chlorides, including challenging ortho-substituted benzylic chloride substrates. Mechanistic investigations implicate a stereoconvergent pathway involving carbon-centered radical intermediates.


2018 ◽  
Author(s):  
Yiming Zhao ◽  
Huy van Nguyen ◽  
Louise Male ◽  
Philip Craven ◽  
Benjamin R. Buckley ◽  
...  

<div>Twelve 1,5-disubtituted and fourteen 5-substituted 1,2,3-triazole derivatives bearing diaryl or dialkyl phosphines at the 5-position were synthesised and used as ligands for palladium-catalysed Suzuki-Miyaura cross-coupling reactions. Bulky substrates were tested, and lead-like product formation was demonstrated. The online tool SambVca 2.0 was used to assess steric parameters of ligands and preliminary buried volume determination using XRD obtained data in a small number of cases proved to be informative. Two modelling approaches were compared for the determination of</div><div>the buried volume of ligands where XRD data was not available. An approach with imposed steric restrictions was found to be superior in leading to buried volume determinations that closely correlate with observed reaction conversions. The online tool LLAMA was used to determine lead-likeness of potential Suzuki-Miyaura cross-coupling products, from which ten of the most lead-like were successfully synthesised. Thus, confirming these readily accessible triazole-containing phosphines as highly suitable ligands for reaction screening and optimisation in drug discovery campaigns.</div>


2019 ◽  
Author(s):  
Victor Bloemendal ◽  
Floris P. J. T. Rutjes ◽  
Thomas J. Boltje ◽  
Daan Sondag ◽  
Hidde Elferink ◽  
...  

<p>In this manuscript we describe a modular pathway to synthesize biologically relevant (–)-<i>trans</i>-Δ<sup>8</sup>-THC derivatives, which can be used to modulate the pharmacologically important CB<sub>1</sub> and CB<sub>2</sub> receptors. This pathway involves a one-pot Friedel-Crafts alkylation/cyclization protocol, followed by Suzuki-Miyaura cross-coupling reactions and gives rise to a series of new Δ<sup>8</sup>-THC derivatives. In addition, we demonstrate using extensive NMR evidence that similar halide-substituted Friedel-Crafts alkylation/cyclization products in previous articles were wrongly assigned as the para-isomers, which also has consequence for the assignment of the subsequent cross-coupled products and interpretation of their biological activity. </p> <p>Considering the importance of the availability of THC derivatives in medicinal chemistry research and the fact that previously synthesized compounds were wrongly assigned, we feel this research is describing a straightforward pathway into new cannabinoids.</p>


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