Here, we report a toolbox strategy to cross-couple unactivated secondary alkyl iodides with various N-, O-, and C-based nucleophiles. This strategy harnesses the ability of photoredox-generated ...phenyl radicals to mediate halogen-atom transfer (XAT) and convert alkyl iodides into the corresponding radicals. These species engage in a second catalytic cycle, mediated by copper, which enables C–N/O/C bond formation with the various nucleophiles.
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•A copper-catalyzed carbonylation of alkyl iodides with phenols is described.•Various phenols were transformed into the corresponding esters in good yields.•Aliphatic alcohols were ...also suitable partners in this reaction.
A copper-catalyzed carbonylation of alkyl iodides with phenols is described. Various phenols were transformed into the corresponding esters in good yields. Aliphatic alcohols were also suitable partners in this reaction.
Halide methyltransferases (HMTs) enable the enzymatic synthesis of S‐adenosyl‐l‐methionine (SAM) from S‐adenosyl‐l‐homocysteine (SAH) and methyl iodide. Characterisation of a range of naturally ...occurring HMTs and subsequent protein engineering led to HMT variants capable of synthesising ethyl, propyl, and allyl analogues of SAM. Notably, HMTs do not depend on chemical synthesis of methionine analogues, as required by methionine adenosyltransferases (MATs). However, at the moment MATs have a much broader substrate scope than the HMTs. Herein we provide an overview of the discovery and engineering of promiscuous HMTs and how these strategies will pave the way towards a toolbox of HMT variants for versatile chemo‐ and regioselective biocatalytic alkylations.
Naturally occurring and engineered promiscuous halide methyltransferases (HMTs) enable S‐adenosyl‐l‐methionine analogues to be enzymatically synthesised and recycled, using simple and readily available alkyl iodides as alkyl donors. In combination with promiscuous methyltransferases (MTs), they dramatically expand the bioalkylation toolbox.
The combining of charge-transfer complex and light irradiation offers a promising solution for the requests of sustainable chemistry. Herein, we developed a phosphine-catalyzed visible light-induced ...alkoxycarbonylation of alkyl iodides with phenols and ethers. Based on the electron donor-acceptor photoactivation strategy, the reaction can be realized at atmospheric pressure of CO under transition metal-free conditions. This promising approach demonstrates high functional group tolerance and excellent chemoselectivity. Additionally, five-component perfluoroalkylative carbonylation for the synthesis of β-perfluoroalkyl acyloxy esters from unactivated olefins and perfluoroalkyl iodides can be realized as well. Moreover, due to the excellent performance of the gram-scale reaction and 13CO results, it provides potential opportunities for large-scale production and other applications.
We have developed an interesting phosphine-catalyzed carbonylation by charge-transfer complex through photoactivation under atmospheric pressure of CO. Five-component perfluoroalkylative carbonylation for the synthesis of β-perfluoroalkyl acyloxy esters from unactivated olefins and perfluoroalkyl iodides can be realized as well. Notably, a series of carbon-13 labeled products were also obtained in good to excellent yields by using 1 bar of 13CO.
A new and convenient copper-catalyzed synthesis of alkyl sulfides has been accomplished using S-alkyl butanethioate as a thiol source. This catalytic protocol displayed a good functional groups ...tolerance and high efficiency. Both secondary and primary alkyl iodides can be used in this procedure. In addition, this method features operational simplicity and a wide substrate range, providing a complementary method for alkyl sulfide synthesis without requiring toxic thiols and noble metals.
A simple protocol for the preparation of N-protected amino alkyl thiols is reported that employs a reaction of sodium trithiocarbonate (Na2CS3) with N-protected amino alkyl iodides. Na2CS3 is easy to ...prepare and the protocol circumvents the use of strong bases and multiple steps. All the thiol compounds made were obtained as enantiopure samples and were characterized employing NMR and mass spectrometry. PUBLICATION ABSTRACT
A new cobalt(II)–Schiff base complex has been prepared and characterized; its electrochemistry has been investigated, catalytic reduction of 1-iododecane by the corresponding electrogenerated ...cobalt(I) species has been probed, and the complex has been anodically polymerized onto glassy carbon. Display omitted
A new tetradentate cobalt(II)–Schiff base complex has been synthesized via the reaction of the ligand 2,2′-((1E,1′E)-(ethane-1,2-diylbis(azanylylidene))bis(ethan-1-yl-1-ylidene))bis(4-((methyl(phenyl)amino)methyl)phenol) with a stoichiometric amount of cobalt(II) acetate tetrahydrate in absolute ethanol. This cobalt(II) complex has been characterized with the aid of several spectroscopic techniques (FT-IR, UV–Vis, and mass spectrometry) as well as by thermal (TGA and DTA) and elemental analysis. Cyclic voltammetry has been employed to examine the redox behavior of the cobalt(II) complex in dimethylformamide (DMF) containing 0.10M tetra-n-butylammonium tetrafluoroborate (TBABF4). In addition, the electrogenerated cobalt(I) form of the complex has been (a) employed as a catalyst for the reduction of 1-iododecane and (b) compared with the behavior of cobalt(I) salen. Finally, the cobalt(II) complex has been subjected to anodic electropolymerization onto the surface of a glassy carbon electrode in DMF containing 0.10M tetra-n-butylammonium perchlorate (TBAP).
•Develop photoionization electron attachment ion mobility spectrometry (PI-EA-IMS) to study electron attachment reaction.•Successfully determine the rate constants of electron attachment to CCl4, ...C2H5I, 1-C3H7I, 1-C4H9I and 2-C3H7I.•Reasonably explain the differences in electron attachment rate constants.
The photoionization electron attachment ion mobility spectrometry (PI-EA-IMS), with photoelectrons formed by photoionization of organic compound like acetone, has been developed to study electron attachment reactions. With this apparatus, the rate constants for electron attachment to alkyl iodides including ethyl iodide (C2H5I), 1-propyl iodide (1-C3H7I), 1-butane iodide (1-C4H9I) and 2-propyl iodide (2-C3H7I) have been determined over the average electron energy from 0.29 to 0.96eV. The rate constants are in the order of magnitude of ∼10−9cm3molecule−1s−1. The experimental measurements show that for straight-chain alkyl iodides, the values of the rate constants follow the order of: k(C2H5I)<k(1-C3H7I)≈k(1-C4H9I) which can be explained by the energy threshold for the formation of iodine anion via dissociative electron attachment. For the isomers, 2-C3H7I has a lower rate constant than 1-C3H7I which may be caused by the effect of branched chain.
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