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[Display omitted] The microwave-assisted cycloaddition of 2,6-disubstituted benzonitrile oxides to 1-iodobuta-1,3-diynes occurs at the iodo-substituted triple bond giving predominantly 5-alkynyl-4-iodo-1,2,3-isoxazoles. The Suzuki–Miyaura and Sonogashira cross-coupling reactions were used for the modification of the thus obtained 4-iodoisoxazoles. [ABSTRACT FROM AUTHOR]

Non‐covalent interactions such as coordination of an organolithium reagent by a directing group and steric repulsion of substituents strongly affect the halogen‐lithium exchange process. Here we present the manifestation of the "buttressing effect" – an indirect interaction between two substituents issued by the presence of a third group – and its influence on the ease and selectivity of the bromine‐lithium exchange and the reactivity of formed aryllithiums. The increase of the size of the "buttressing" substituent strongly affects the conformation of a NMe2 group, forcing it to hinder ortho‐bromine and thus slowing down the exchange. In naphthalene substrates bearing two bromines, this suppresses regioselectivity of the reaction. The "buttressing effect" forces formed aryllithiums to deaggregate, thus boosting their reactivity. This facilitates the decomposition via protolisys by ethereal solvents even at low temperatures and in some cases initiates fast Wurtz‐Fittig coupling. [ABSTRACT FROM AUTHOR]

Cu-catalyzed 1,3-dipolar cycloaddition of methyl 2-azidoacetate to iodobuta-1,3-diynes and subsequent Suzuki-Miyaura cross-coupling were used to synthesize new triazoles derivatives: 5-aryl-4-arylethynyl-1H-1,2,3-triazoles. Investigation of their optical properties by using UV absorption and fluorescence emission spectroscopies revealed that all molecules possess fluorescence properties with the values of the Stokes shift more than 100 nm. The photophysical behavior of the two most promising triazoles in polar and non-polar solvents was also studied. [ABSTRACT FROM AUTHOR]

Non-covalent interactions such as coordination of an organolithium reagent by a directing group and steric repulsion of substituents strongly affect the halogen-lithium exchange process. Here we present the manifestation of the "buttressing effect" - an indirect interaction between two substituents issued by the presence of a third group - and its influence on the ease and selectivity of the bromine-lithium exchange and the reactivity of formed aryllithiums. The increase of the size of the "buttressing" substituent strongly affects the conformation of a NMe 2 group, forcing it to hinder ortho-bromine and thus slowing down the exchange. In naphthalene substrates bearing two bromines, this suppresses regioselectivity of the reaction. The "buttressing effect" forces formed aryllithiums to deaggregate, thus boosting their reactivity. This facilitates the decomposition via protolisys by ethereal solvents even at low temperatures and in some cases initiates fast Wurtz-Fittig coupling., (© 2023 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)