67460-10-0Relevant articles and documents
A facile and versatile electro-reductive system for hydrodefunctionalization under ambient conditions
Huang, Binbin,Guo, Lin,Xia, Wujiong
supporting information, p. 2095 - 2103 (2021/03/26)
A general electrochemical system for reductive hydrodefunctionalization is described, employing the inexpensive and easily available triethylamine (Et3N) as a sacrificial reductant. This protocol is characterized by facile operation, sustainable conditions, and exceptionally wide substrate scope covering the cleavage of C-halogen, N-S, N-C, O-S, O-C, C-C and C-N bonds. Notably, the selectivity and capability of reduction can be conveniently switched by simple incorporation or removal of an alcohol as a co-solvent.
Ynoate-Initiated Selective C-N Esterification of Tertiary Amines under Transition-Metal and Oxidant-Free Conditions
Sun, Feixiang,Feng, Huangdi,Huang, Liliang,Huang, Junhai
supporting information, p. 713 - 717 (2021/01/14)
An efficient and selective method for metal-and oxidant-free deaminated esterification of tertiary amines is presented. In this protocol, ynoates play a key role to activate the Csp 3-N bond through a process of in situ generation of zwitterionic salts. The transformations show that Csp 3-N bond in the zwitterionic species has a lower dissociation energy than Csp 2-N bond, leading to break preferentially and be trapped by carboxylic acids to generate the corresponding products in moderate to good yield.
Copper-Catalyzed Oxyalkynylation of C-S Bonds in Thiiranes and Thiethanes with Hypervalent Iodine Reagents
Borrel, Julien,Pisella, Guillaume,Waser, Jerome
supporting information, p. 422 - 427 (2020/01/31)
We report the oxyalkynylation of thiiranes and thietanes using ethynylbenziodoxolone reagents (EBXs) to readily access functionalized building blocks bearing an alkynyl, a benzoate, and an iodide group. The reaction proceeds with high atom efficiency most
Metal-Free Synthesis of 4-Chloroisocoumarins by TMSCl-Catalyzed NCS-Induced Chlorinative Annulation of 2-Alkynylaryloate Esters
Norseeda, Krissada,Chaisan, Nattawadee,Thongsornkleeb, Charnsak,Tummatorn, Jumreang,Ruchirawat, Somsak
, p. 16222 - 16236 (2019/12/25)
4-Chloroisocoumarins can be conveniently prepared from 2-alkynylaryloate esters via the activation of alkynes by electrophilic chlorine, generated in situ from N-chlorosuccinimide (NCS) in the presence of 10 mol % trimethylsilyl chloride (TMSCl), which leads to 6-endo-dig-selective chlorinative annulation to give the desired products in moderate to quantitative yields. The procedure employs readily available reagents and can be conveniently carried out on a wide scope of substrates under mild conditions (0 °C to rt). Furthermore, the reaction is scalable for gram-scale preparation of 4-chloroisocoumarins. Additionally, 4-bromo- and 4-iodoisocoumarins can be prepared in moderate to good yields by replacing NCS with N-bromosuccinimide (NBS) and N-iodosuccinimide (NIS), respectively.
Programmed twisting of phenylene-ethynylene linkages from aromatic stacking interactions
Mullin, William J.,Pawle, Robert H.,Sharber, Seth A.,Müller, Peter,Thomas, Samuel W.
, p. 1198 - 1207 (2019/02/07)
Control over the conformation and packing of conjugated materials is an unsolved problem that prevents the rational design of organic optoelectronics, such as preventing self-quenching of luminescent molecules. Exacerbating this challenge is a general lack of widely applicable strategies for controlling packing with discrete, directional non-covalent interactions. Here, we present a series of conjugated molecules with diverse backbones of three or four arenes that feature pentafluorobenzyl ester substituents. Nearly all the compounds reveal intramolecular stacking interactions between the fluoroarene (ArF) side-chains and non-fluorinated arenes (ArH) in the middle of the chromophores; a twisted PE linkage accompanies each example of this intramolecular ArF-ArH stacking. Furthermore, these molecules can resist dramatic changes to emission upon transition from organic solution to thin film when ArF rings prevent interchromophore interactions. By broadening the structural space of conjugated backbones over which ArF-ArH stacking can twist PE linkages reliably and prevent self-quenching of solids with simple synthetic approaches, this work suggests fluorinated benzyl ester substituents adjacent to phenylene ethynylene linkages as supramolecular synthons for the crystal engineering of organic optoelectronic materials.
Carboxylate-Assisted Oxidative Addition to Aminoalkyl PdII Complexes: C(sp3)?H Arylation of Alkylamines by Distinct PdII/PdIV Pathway
Whitehurst, William G.,Blackwell, J. Henry,Hermann, Gary N.,Gaunt, Matthew J.
supporting information, p. 9054 - 9059 (2019/06/04)
Reported is the discovery of an approach to functionalize secondary alkylamines using 2-halobenzoic acids as aryl-transfer reagents. These reagents promote an unusually mild carboxylate-assisted oxidative addition to alkylamine-derived palladacycles. In the presence of AgI salts, a decarboxylative C(sp3)?C(sp2) bond reductive elimination leads to γ-aryl secondary alkylamines and renders the carboxylate motif a traceless directing group. Stoichiometric mechanistic studies were effectively translated to a Pd-catalyzed γ-C(sp3)?H arylation process for secondary alkylamines.
K2S2O8-promoted [2+2]-cycloaddition of benzyl-2-(3-hydroxypropynyl)-benzoates: A new route to polysubstituted cyclobutanes
Zhu, Hai-Tao,Tong, Xiao-Juan,Zhou, Ni-Ni,Yang, De-Suo,Fan, Ming-Jin
supporting information, p. 5497 - 5500 (2016/11/19)
An efficient and convenient metal-free [2+2]-cycloaddition of benzyl-2-(3-hydroxypropynyl)-benzoates via allene processes has been developed, which provides impressive access to fused cyclobutanes from easily accessed π-components. This transformation involved the cleavage of two C–O bonds, the formations of two C–O bonds and two C–C bonds and showed some advantages, including mild conditions and wide substrate scope.
Transition metal free oxidative esterification of alcohols with toluene
Liu, Lianghui,Yun, Lin,Wang, Zikuan,Fu, Xuefeng,Yan, Chun-Hua
supporting information, p. 5383 - 5386 (2013/09/12)
Using Bu4NI as the catalyst and tert-butyl hydroperoxide as the oxidant, direct esterification of alcohols with toluene derivatives was achieved. Mechanistic investigations indicate that the alcohols are sequentially oxidized to aldehydes, carboxylic acids, and then to benzyl esters. Bu 4N+ functions as a phasetransfer reagent and iodide catalyzes the reaction.
Straightforward reductive esterification of carbonyl compounds with carboxylic acids through tosylhydrazone intermediates
Garcia-Munoz, Angel-Humberto,Tomas-Gamasa, Maria,Perez-Aguilar, M. Carmen,Cuevas-Yanez, Erick,Valdes, Carlos
supporting information; experimental part, p. 3925 - 3928 (2012/08/28)
The reaction of carboxylic acids with tosylhydrazones in basic media gives rise to the corresponding esters through an O-H insertion reaction in the in situ generated diazo compound. The process is operationally very simple, catalyst free, and very general with regard to the structure of both coupling partners. In particular, the esterification can be accomplished by employing tosylhydrazones derived from enolizable carbonyl compounds. Considering the ready availability of tosylhydrazones from carbonyl compounds, this reaction can be visualized as a reductive esterification of carbonyl compounds.
Nitromethane with IBX/TBAF as a nitrosating agent: Synthesis of nitrosamines from secondary or tertiary amines under mild conditions
Potturi, Hima K.,Gurung, Ras K.,Hou, Yuqing
body text, p. 626 - 631 (2012/02/16)
Aliphatic or aromatic N,N-disubstituted nitrosamine was generated in fair to excellent yield from the reaction of a secondary or tertiary amine with o-iodoxybenzoic acid (IBX) or o-iodosylbenzoic acid (IBA)/R4NX (X = halide) and nitromethane. The product yield was strongly influenced by both the halide of R4NX and iodanes. IBX gave a higher yield than IBA, while the halides follow F- > Cl- > Br- ～ I-. Nitrous acid formed in situ from nitromethane and IBX (or IBA)/halides is likely responsible for the observed reaction.
