The solid-phase reductive alkylation of the Lys side chain in positions 6 (D) and 8 (L) and position 8 alone of the LH-RH antagonist [N-Ac-D-Nal,D-Ph2,3,D-Arg6,Phe7,D-Ala10]LH-RH was investigated in an attempt to reduce the histamine-releasing activity inherent to most potent antagonists while retaining high antiovulatory activity. The protected parent analogues were prepared by conventional solid-phase peptide synthesis. After selective removal of the Lys Fmoc side chain protection, the resin-bound peptides were readily and conveniently alkylated at the epsilon amino groups with various aldehydes and ketones in the presence of NaBH3CN. The analogues were then cleaved from the resin with simultaneous deprotection by anhydrous hydrogen fluoride and purified to homogeneity in two stages: gel permeation followed by preparative reversed-phase liquid chromatography. The analogues were assayed in standard rat antiovulatory and in vitro histamine-release assays.
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http://dx.doi.org/10.1021/jm00393a038 | DOI Listing |
Org Lett
January 2025
School of Environmental and Chemical Engineering, Wuyi University, Jiangmen 529090, P. R. China.
We have realized a cathodic deoxygenative alkylation between nitro(hetero)arenes and organic halides, employing bis(pinacolato)diboron (Bpin) and LiCl as additives to trap and stabilize the generated alkyl radicals and carbanions, thereby facilitating efficient N-O cleavage and selective C-N bond formation. The protocol offers an economical method for the efficient synthesis of multiple aromatic(hetero) amines, without the need for reactive reductants and the exclusion of air and moisture. Notably, the protocol is distinguished by scalability, broad functional group compatibility, and safe and mild conditions, demonstrating practicality in the synthesis and late-stage modification of various bioactive compounds.
View Article and Find Full Text PDFPharmaceuticals (Basel)
January 2025
Departamento de Farmacia, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Av. Wilfrido Massieu 399, Mexico City C.P. 07738, Mexico.
: In recent years the global incidence of cancer during pregnancy is rising, occurring in 1 out of every 1000 pregnancies. In this regard, the most used chemotherapy drugs to treat cancer are alkylating agents such as cyclophosphamide (Cp). Despite its great efficacy, has been associated with the production of oxidative stress and DNA damage, leading to embryotoxicity, genotoxicity, and teratogenicity in the developing .
View Article and Find Full Text PDFOrg Lett
January 2025
Department of Chemistry and Materials Science, College of Science, Nanjing Forestry University, Nanjing 210037, China.
The Nozaki-Hiyama-Kishi reaction offers effective and reliable strategies for the preparation of alcohols via carbon-carbon bond formation. Typical methods usually require stoichiometric amounts of chromium salts, co-transition metals, and auxiliary reagents, which limits their practical application in industrial chemistry. To mitigate these limitations, substantial efforts have been made to develop chromium-catalytic approaches.
View Article and Find Full Text PDFJ Org Chem
January 2025
Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Materials Sciences, Zhejiang Normal University, 688 Yingbin Road, Jinhua 321004, P. R. China.
-Difluorohomoallyl amines, an important class of -difluoroalkenes, are prevalent moieties in many bioactive compounds. However, limited methods are suitable for the synthesis of this type of compound containing secondary amines. Here, we display a photocatalytic multicomponent protocol for the synthesis of -difluoroalkenes containing secondary amines, which makes use of readily available materials: arylamines, alkyl aldehydes, and α-trifluoromethyl alkenes.
View Article and Find Full Text PDFNat Commun
January 2025
Flow Chemistry Group, Van't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Amsterdam, The Netherlands.
Secondary amines are vital functional groups in pharmaceuticals, agrochemicals, and natural products, necessitating efficient synthetic methods. Traditional approaches, including N-monoalkylation and reductive amination, suffer from limitations such as poor chemoselectivity and complexity. Herein, we present a streamlined deoxygenative photochemical alkylation of secondary amides, enabling the efficient synthesis of α-branched secondary amines.
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