Differences in regioselectivity were observed during the S(N)Ar reaction of amines with unsymmetrical 3,5-dichloropyrazines. This study revealed that when the 2-position of the pyrazine was occupied with an electron-withdrawing group (EWG), nucleophilic attack occurred preferentially at the 5-position. When the 2-position was substituted with an electron-donating group (EDG), nucleophilic attack occurred preferentially at the 3-position. These results are reported along with a computational rationale for the experimental observations based on the Fukui index at the reacting centers.
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http://dx.doi.org/10.1021/ol4006695 | DOI Listing |
RSC Med Chem
December 2024
Modality Platform Technologies, GSK Stevenage SG1 2NY UK
High-throughput chemistry (HTC) and direct-to-biology (D2B) platforms allow for plate-based compound synthesis and biological evaluation of crude mixtures in cellular assays. The rise of these workflows has rapidly accelerated drug-discovery programs in the field of targeted protein degradation (TPD) in recent years by removing a key bottleneck of compound purification. However, the number of chemical transformations amenable to this methodology remain minimal, leading to limitations in the exploration of chemical space using existing library-based approaches.
View Article and Find Full Text PDFBioorg Chem
December 2024
Laboratory for Drug Design and Synthesis, Department of Pharmaceutical Sciences and Natural Products, School of Health Sciences, Central University of Punjab, Bathinda 151 401, India. Electronic address:
In this study, we herein report the design, synthesis, and anticancer assessment of a series of new 4-substituted 5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidines. The synthesis involved key intermediates such as the 2-aminoester derivative, which underwent a series of reactions to produce compounds 7a-7t. The optimized SAr reactions, utilizing microwave irradiation in DMF, led to high yields and efficient preparation of the desired compounds.
View Article and Find Full Text PDFFront Chem
November 2024
Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
Introduction: The increasing prevalence of antibiotic-resistant pathogens necessitates the urgent development of new antibacterial agents. Concurrently, synthetic chemistry is moving towards more sustainable practices that minimize environmental impact. This study aims to synthesize 3-aryl-2-benzo[b][1,4]oxazin-2-one derivatives, including the natural product cephalandole A, using a sustainable approach that avoids metal catalysts.
View Article and Find Full Text PDFJ Org Chem
December 2024
School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9ST, U.K.
Nucleophilic aromatic substitutions (SAr) of alkoxides on pentafluoroaryl ethers are explored as a first step in a synthesis sequence to generate all- 2,3,5,6-tetrafluorocyclohexyl-1,4-dialkyl ethers . The SAr reaction was explored both experimentally and theoretically to rationalize // selectivities. -Butyl deprotection of products followed by phenol alkylations introduces versatility to the synthesis.
View Article and Find Full Text PDFInt J Mol Sci
November 2024
Institute of Fine Organic Chemistry of A. L. Mnjoyan, Scientific Technological Center of Organic and Pharmaceutical Chemistry of National Academy of Science of Republic of Armenia, Ave. Azatutyan 26, Yerevan 0014, Armenia.
Herein we describe the synthesis and rearrangement of 1,3-diamino-2,7-naphthyridines and 1-amino-3-oxo-2,7-naphthyridines. In the case of 1,3-diamino-2,7-naphthyridines, it was found that the rearrangement reaction was influenced by both the substituent at the 7th position of the 2,7-naphthyridine ring and by the nature of the cyclic amine at the 1st position. The influence was mainly steric.
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