Microwave-Controlled Preparation of Alkenyl-(1H)-1,2,4-triazoles: First Heck Reaction on a (1H)-1,2,4-Triazole Moiety

Ángel Díaz-Ortiz; Pilar Prieto; Abel de Cózar; Cristina Cebrián; Andrés Moreno; Antonio de la Hoz

doi:10.1071/ch09185

Microwave-Controlled Preparation of Alkenyl-(1H)-1,2,4-triazoles: First Heck Reaction on a (1H)-1,2,4-Triazole Moiety

Australian Journal of Chemistry ◽

10.1071/ch09185 ◽

2009 ◽

Vol 62 (12) ◽

pp. 1600 ◽

Cited By ~ 3

Author(s):

Ángel Díaz-Ortiz ◽

Pilar Prieto ◽

Abel de Cózar ◽

Cristina Cebrián ◽

Andrés Moreno ◽

...

Keyword(s):

Heck Reaction ◽

Cross Coupling ◽

Synthetic Approach ◽

Heck Reactions ◽

Triazole Derivatives ◽

Synthetic Procedure ◽

Wide Range ◽

Controlled Preparation

A new synthetic approach for the preparation of alkenyl-1,2,4-triazole derivatives based on microwave-induced C–C cross-coupling Heck reactions is described. To the best of our knowledge, this is the first application of the Heck reaction to a dihalogenated 1,2,4-triazole. This approach allows the introduction of a wide range of equivalent or different alkenyl substituents in the 5- and/or 3-positions, thus extending the possibilities for the preparation of these valuable derivatives. A similar microwave-induced synthetic procedure has also been applied to the Heck reaction of 4-vinyl-1,2,3-triazoles.

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Reductive Cross-Coupling of Vinyl Electrophiles

Synthesis ◽

10.1055/s-0040-1707342 ◽

2020 ◽

Vol 52 (24) ◽

pp. 3751-3763 ◽

Cited By ~ 1

Author(s):

Xing-Zhong Shu ◽

Xiaobo Pang ◽

Xuejing Peng

Keyword(s):

Transition Metal ◽

Heck Reaction ◽

Structural Complexity ◽

Cross Coupling ◽

Heck Reactions ◽

Promising Tool ◽

Transition Metal Catalyzed ◽

Metal Catalyzed

The synthesis of alkenes (olefins) is a central subject in the synthetic community. The transition-metal-catalyzed reductive cross-coupling of vinyl electrophiles has emerged as a promising tool to produce alkenes with improved flexibility, structural complexity, and functionality tolerance. In this review, we summarized the progress in this field with respect to cross-electrophile couplings and reductive Heck reactions using vinyl electrophiles.1 Introduction2 Cross-Electrophile Coupling of Vinyl Electrophiles3 Reductive Heck Reaction of Vinyl Electrophiles4 Summary and Outlook

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Pd-catalyzed intermolecular dehydrogenative Heck reactions of six membered heteroarenes

Current Organic Chemistry ◽

10.2174/1385272825666210412160959 ◽

2021 ◽

Vol 25 ◽

Author(s):

Jean Le Bras ◽

Jacques Muzart

Keyword(s):

Heck Reaction ◽

Cross Coupling ◽

Present Review ◽

Heck Reactions ◽

Intensive Research ◽

The Subject

: The PdII-mediated cross-coupling of (hetero)arenes with alkenes may be an effective method for the formation of a C–C bond from two C–H bonds. Discovered by Fujiwara and co-workers in 1967, this reaction led to a number of reports that we firstly highlighted in 2011 (review with references till June 2010) and for which, we retained the name “dehydrogenative Heck reaction” (DHR). The DHR of six-membered heteroarenes, has been the subject of intensive research over the last ten years. The present review is limited to these dehydrogenative Heck reactions published since 2010, underlining the diversity of the procedures and, with personal comments, the mechanisms and intermediates that have been proposed.

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Pd-Catalyzed Intermolecular Dehydrogenative Heck Reactions of Five-Membered Heteroarenes

Catalysts ◽

10.3390/catal10050571 ◽

2020 ◽

Vol 10 (5) ◽

pp. 571

Author(s):

Jean Le Bras ◽

Jacques Muzart

Keyword(s):

Heck Reaction ◽

Cross Coupling ◽

Present Review ◽

Heck Reactions ◽

Intensive Research ◽

The Subject

The Pd-mediated cross-coupling of (hetero)arenes with alkenes may be an effective method for the formation of a C–C bond from two C–H bonds. Discovered by Fujiwara and co-workers in 1967, this reaction led to a number of reports that we firstly highlighted in 2011 (review with references till June 2010) and for which, we retained the name “dehydrogenative Heck reaction”. The topic, especially the reactions of five-membered heteroarenes, has been the subject of intensive research over the last ten years. The present review is limited to these dehydrogenative Heck reactions published since 2010, underlining the progress of the procedures.

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Studies in Porphyrin Chemistry: A Synthetic Approach

Australian Journal of Chemistry ◽

10.1071/ch9911163 ◽

1991 ◽

Vol 44 (9) ◽

pp. 1163 ◽

Cited By ~ 26

Author(s):

PS Clezy

Keyword(s):

Oxidative Cyclization ◽

Mechanistic Study ◽

Synthetic Approach ◽

General Strategy ◽

Substitution Pattern ◽

Synthetic Procedure ◽

Wide Range ◽

Porphyrin Synthesis ◽

Broad Understanding

This review summarizes porphyrin synthesis in the author's laboratory, and deals mainly with the preparation of porphyrins substituted with electron-withdrawing groups. Oxidative cyclization of 1,19-dimethylbilenes-b has provided the most successful avenue to porphyrins of this class, and the procedure works best when the terminal rings of the bilene -b are substituted with electron-withdrawing groups. This methodology has yielded a wide range of porphyrins carrying this class of substituent on adjacent pyrrolic rings, and has led to the preparation of many biologically important molecules including porphyrin a and the chlorophylls c1 and c2. Also described are the necessary modifications which are required to adapt the general strategy to the synthesis of porphyrins carrying electron-withdrawing groups on opposite pyrrolic rings as well as for cases where only one such substituent occurs. All these procedures were designed specifically to handle the preparation of porphyrins which were unsymmetrically substituted. However, some biologically significant members of the porphyrin series have a symmetrical arrangement of substituents in part of the molecule, and an adaption of the general synthetic procedure allows advantage to be taken of this substitution pattern. A mechanistic study of the oxidative cyclization of bilenes -b, which has been the reaction central in all the above synthetic endeavours, has produced a broad understanding of the manner in which the cyclization proceeds. Very recent studies involving the synthesis of petroporphyrins, besides consolidating the structure of many of these compounds, have provided sufficient material to allow an investigation of the properties of these porphyrins to commence, and in some cases this had led to a clearer understanding of their orgin.

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Phosphino-Triazole Ligands for Palladium-Catalysed Cross-Coupling

10.26434/chemrxiv.6823259 ◽

2018 ◽

Author(s):

Yiming Zhao ◽

Huy van Nguyen ◽

Louise Male ◽

Philip Craven ◽

Benjamin R. Buckley ◽

...

Keyword(s):

Drug Discovery ◽

Cross Coupling ◽

Product Formation ◽

Coupling Reactions ◽

Volume Determination ◽

Online Tool ◽

Triazole Derivatives ◽

Cross Coupling Reactions ◽

Modelling Approaches

<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>

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General Cyclopropane Assembly via Enantioselective Redox-Active Carbene Transfer to Aliphatic Olefins

10.26434/chemrxiv.7436795 ◽

2018 ◽

Author(s):

Marc Montesinos-Magraner ◽

Matteo Costantini ◽

Rodrigo Ramirez-Contreras ◽

Michael E. Muratore ◽

Magnus J. Johansson ◽

...

Keyword(s):

Total Synthesis ◽

Asymmetric Synthesis ◽

Chemical Space ◽

Synthetic Approach ◽

Asymmetric Cyclopropanation ◽

Redox Active ◽

Wide Range ◽

Leaving Group ◽

Stereoelectronic Properties ◽

Carbene Transfer

Asymmetric cyclopropane synthesis currently requires bespoke strategies, methods, substrates and reagents, even when targeting similar compounds. This limits the speed and chemical space available for discovery campaigns. Here we introduce a practical and versatile diazocompound, and we demonstrate its performance in the first unified asymmetric synthesis of functionalized cyclopropanes. We found that the redox-active leaving group in this reagent enhances the reactivity and selectivity of geminal carbene transfer. This effect enabled the asymmetric cyclopropanation of a wide range of olefins including unactivated aliphatic alkenes, enabling the 3-step total synthesis of (–)-dictyopterene A. This unified synthetic approach delivers high enantioselectivities that are independent of the stereoelectronic properties of the functional groups transferred. Our results demonstrate that orthogonally-differentiated diazocompounds are viable and advantageous equivalents of single-carbon chirons<i>.</i>

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Potential Triazole-based Molecules for the Treatment of Neglected Diseases

Current Medicinal Chemistry ◽

10.2174/0929867324666170727103901 ◽

2019 ◽

Vol 26 (23) ◽

pp. 4403-4434 ◽

Cited By ~ 5

Author(s):

Susimaire Pedersoli Mantoani ◽

Peterson de Andrade ◽

Talita Perez Cantuaria Chierrito ◽

Andreza Silva Figueredo ◽

Ivone Carvalho

Keyword(s):

Effective Treatment ◽

Chagas Disease ◽

Medicinal Chemistry ◽

Biological Activities ◽

Neglected Diseases ◽

Triazole Derivatives ◽

Wide Range ◽

The World ◽

Great Relevance ◽

The Moment

Neglected Diseases (NDs) affect million of people, especially the poorest population around the world. Several efforts to an effective treatment have proved insufficient at the moment. In this context, triazole derivatives have shown great relevance in medicinal chemistry due to a wide range of biological activities. This review aims to describe some of the most relevant and recent research focused on 1,2,3- and 1,2,4-triazolebased molecules targeting four expressive NDs: Chagas disease, Malaria, Tuberculosis and Leishmaniasis.

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Monodentate Trialkylphosphines: Privileged Ligands in Metal-catalyzed Crosscoupling Reactions

Current Organic Chemistry ◽

10.2174/1385272824666200211114540 ◽

2020 ◽

Vol 24 (3) ◽

pp. 231-264 ◽

Cited By ~ 3

Author(s):

Kevin H. Shaughnessy

Keyword(s):

Transition Metal ◽

Cross Coupling ◽

Coupling Reactions ◽

Cross Coupling Reactions ◽

Aryl Bromides ◽

Wide Range ◽

Sterically Demanding ◽

Transition Metal Catalyzed ◽

Catalyzed Reactions ◽

Metal Catalyzed

Phosphines are widely used ligands in transition metal-catalyzed reactions. Arylphosphines, such as triphenylphosphine, were among the first phosphines to show broad utility in catalysis. Beginning in the late 1990s, sterically demanding and electronrich trialkylphosphines began to receive attention as supporting ligands. These ligands were found to be particularly effective at promoting oxidative addition in cross-coupling of aryl halides. With electron-rich, sterically demanding ligands, such as tri-tertbutylphosphine, coupling of aryl bromides could be achieved at room temperature. More importantly, the less reactive, but more broadly available, aryl chlorides became accessible substrates. Tri-tert-butylphosphine has become a privileged ligand that has found application in a wide range of late transition-metal catalyzed coupling reactions. This success has led to the use of numerous monodentate trialkylphosphines in cross-coupling reactions. This review will discuss the general properties and features of monodentate trialkylphosphines and their application in cross-coupling reactions of C–X and C–H bonds.

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