6904-17-2Relevant academic research and scientific papers
Inherent Reactivity of Spiro-Activated Electrophilic Cyclopropanes
Jüstel, Patrick M.,Ofial, Armin R.,Pignot, Cedric D.,Stan, Alexandra
supporting information, p. 15928 - 15935 (2021/10/25)
The kinetics of the ring-opening reactions of thiophenolates with geminal bis(acceptor)-substituted cyclopropanes in DMSO at 20 °C was monitored by photometric methods. The determined second-order rate constants of the SN2 reactions followed linear relationships with Mayr nucleophilicity parameters (N/sN) and Br?nsted basicities (pKaH) of the thiophenolates as well as with Hammett substituent parameters (σ) for groups attached to the thiophenolates. Phenyl-substituted cyclopropanes reacted by up to a factor of 15 faster than their unsubstituted analogues, in accord with the known activating effect of adjacent π-systems in SN2 reactions. Variation of the electronic properties of substituents at the phenyl groups of the cyclopropanes gave rise to parabolic Hammett relationships. Thus, the inherent SN2 reactivity of electrophilic cyclopropanes is activated by electron-rich π-systems because of the more advanced C1?C2 bond polarization in the transition state. On the other hand, electron-poor π-systems also lower the energetic barriers for the attack of anionic nucleophiles owing to attractive electrostatic interactions.
Aza-Wittig Reaction with Nitriles: How Carbonyl Function Switches from Reacting to Activating
Tukhtaev, Hamidulla B.,Ivanov, Konstantin L.,Bezzubov, Stanislav I.,Cheshkov, Dmitry A.,Melnikov, Mikhail Ya.,Budynina, Ekaterina M.
supporting information, p. 1087 - 1092 (2019/02/19)
Transformations of α-EWG-substituted (electron-withdrawing group, EWG) γ-azidobutyronitriles proceeding via unusual aza-Wittig reactions between the phosphazene and nitrile functions and affording pyrrole-derived iminophosphazenes were developed. α-EWGs w
Stereoselective Construction of Nitrile-Substituted Cyclopropanes from 2-Substituted Ethenesulfonyl Fluorides via Carbon-Sulfur Bond Cleavage
Liu, Hao,Moku, Balakrishna,Li, Fei,Ran, Jiabing,Han, Jinsong,Long, Sihui,Zha, Gao-Feng,Qin, Hua-Li
supporting information, p. 4596 - 4601 (2019/08/28)
The intermolecular cyclopropanation of 2-aryl and 2-styryl substituted ethenesulfonyl fluorides with active cyano-containing methylene compounds was described. This reaction proceeds via carbon-sulfur bond cleavage under metal-free conditions in up to 99% yield, affording a variety of nitrile-substituted cyclopropanes with high diastereoselectivity. (Figure presented.).
Intermolecular Cyclopropanation of Styrenes Using Iodine and Visible Light via Carbon-Iodine Bond Cleavage
Usami, Kaoru,Nagasawa, Yoshitomo,Yamaguchi, Eiji,Tada, Norihiro,Itoh, Akichika
supporting information, p. 8 - 11 (2016/01/15)
The intermolecular cyclopropanation of aromatic olefins with activated methylene compounds using iodine and visible light irradiation was described. This reaction proceeds under rare-metal-free conditions. Styrenes with various substituted groups (alkyl a
Hypoiodite-mediated catalytic cyclopropanation of alkenes with malononitrile
Yoshimura, Akira,Nicholas Jones,Yusubov, Mekhman S.,Zhdankina, Viktor V.
supporting information, p. 3336 - 3340 (2015/01/16)
An efficient synthetic procedure for di-cyano-cyclopropanation of alkenes using catalytic amounts of molecular iodine as a precatalyst and tert-butyl hydroperoxide (TBHP) as a terminal oxidant under mild conditions has been developed. This catalytic reaction works especially well for the aryl-substituted double bond affording products of cyclopropanation in high yields. A catalytic cycle based on the generated in situ hypoiodite species has been proposed,.
Hypoiodite-mediated cyclopropanation of alkenes
Yoshimura, Akira,Koski, Steven R.,Kastern, Brent J.,Fuchs, Jonathan M.,Jones, T. Nicholas,Yusubova, Roza Y.,Nemykin, Victor N.,Zhdankin, Viktor V.
supporting information, p. 5895 - 5898 (2014/05/20)
An efficient, transition metal-free procedure for the cyclopropanation of alkenes using malononitrile and the LiI-tBuOCl combination under mild reaction conditions is described. The reaction mechanism most likely involves tBuOI generated in situ from LiI and tBuOCl. The utility of this new methodology has been demonstrated by the synthesis of a potential HIV-1 RT inhibitor. An efficient, transition-metal-free procedure for the cyclopropanation of alkenes using malononitrile and the LiI/tBuOCl combination under mild reaction conditions is described. The reaction mechanism most likely involves tBuOI generated in situ from LiI and tBuOCl. The utility of this new methodology has been demonstrated by the synthesis of a potential HIV-1 RT inhibitor (see scheme).
Hypervalent iodine(iii)-mediated cyclopropa(e)nation of alkenes/alkynes under mild conditions
Lin, Shaoxia,Li, Mengru,Dong, Zhiyong,Liang, Fushun,Zhang, Jingping
, p. 1341 - 1350 (2014/03/21)
Hypervalent iodine(iii)-mediated dioxygenation and diamination of alkenes have been previously developed. In this study, the potential application of hypervalent iodine(iii) reagent was successfully extended to the dialkylation and cyclopropa(e)nation of
Ring-opening 1,3-dichlorination of donor-acceptor cyclopropanes by iodobenzene dichloride
Garve, Lennart K.B.,Barkawitz, Philip,Jones, Peter G.,Werz, Daniel B.
supporting information, p. 5804 - 5807 (2015/02/19)
Donor-acceptor cyclopropanes are reacted with iodobenzene dichloride to afford ring-opened products bearing chlorine atoms in the 1- and 3-positions, adjacent to the donor and acceptor groups. A variety of different donors (e.g., alkyl, aryl, N, and O) and acceptor moieties (e.g., ketones, diesters, and dinitriles) are used.
Synthesis of functionalized dihydrothiophenes from doubly activated cyclopropanes using tetrathiomolybdate as the sulfur transfer reagent
Gopinath, Purushothaman,Chandrasekaran, Srinivasan
experimental part, p. 700 - 703 (2011/03/20)
A number of doubly activated cyclopropanes were synthesized starting from various substituted bromosulfonium bromides in good yield. Regioselective ring-opening of cyclopropanes with tetrathiomolybdate as the sulfur transfer reagent gave dihydrothiophenes
Sequential ATRA/reductive cyclopropanation reactions with a ruthenium catalyst in the presence of manganese
Fernandez-Zumel, Mariano A.,Buron, Charlotte,Severin, Kay
experimental part, p. 2272 - 2277 (2011/06/22)
Atom-transfer radical addition (ATRA) reactions of ethyl trichloroacetate, dichloromalononitrile, or diethyl 2,2-dichloromalonate with olefins followed by dechlorination have provided functionalized cyclopropanes in one step. The RuIII complex
