15854-87-2Relevant articles and documents
Microwave-assisted trans-halogenation reactions of various chloro-, bromo-, trifluoromethanesulfonyloxy- and nonafluorobutanesulfonyloxy-substituted quinolines, isoquinolines, and pyridines leading to the corresponding iodinated heterocycles
Bissember, Alex C.,Banwell, Martin G.
, p. 4893 - 4895 (2009)
(Chemical Equation Presented) Microwave irradiation of certain chloro-, bromo-, trifluoromethanesulfonyloxy- and nonafluorobutanesulfonyloxy-substituted quinolines in the presence of acetic anhydride and sodium iodide leads, via a trans-halogenation process, to the corresponding iodides in high yield. Related conversions involving pyridines and isoquinolines can also be achieved under similar conditions.
Acid-Mediated Halogen Exchange in Heterocyclic Arenes: A Highly Effective Iodination Method
Wolf, Christian,Tumambac, Gilbert E.,Villalobos, Cristina N.
, p. 1801 - 1804 (2003)
Heterocyclic arenes including pyridyl, quinolyl, and isoquinolyl chlorides have been converted to their corresponding iodides in good to high yields via acid-mediated nucleophilic halogen exchange with sodium iodide. This procedure avoids the use of transition metals, harsh reaction conditions, and affords highly regioselective halide exchange. Chloride substituents in position 2 and 4 of pyridines and quinolines are readily substituted by iodide in 75-91% and conversion of 1-chloroisoquinoline to its iodide derivative was found to proceed with 90% yield. Positions that are not activated for nucleophilic aromatic substitution proved to be inert to halide exchange. Regioselective chloride/iodide exchange in 4,7-dichloroquinoline hydrochloride gave 7-chloro-4-iodoquinoline, an important precursor of anti-malaria drugs, in almost 90% yield.
Efficient syntheses of 4-iodopyridine and of 4-pyridylboronic acid pinacol ester
Coudret, Christophe
, p. 3543 - 3547 (1996)
4-Iodopyridine can be prepared in good yield by low temperature diazotation-Sandmeyer reaction of the corresponding amine, then efficiently converted to the air-stable pinacol ester of 4-pyridylboronic acid.
A heterofunctional ligand approach for the preparation of high connectivity coordination polymers: Combining a "bridge" and "pillar" in one ligand
Al-Fayaad, Hydar A.,Athukorala Arachchige, Kasun S.,Clegg, Jack K.
, p. 5310 - 5315 (2020/09/03)
Two of the most successful strategies for the preparation of three-dimensional coordination polymers and MOFs are reticular synthesis and pillaring. Here we present a new approach which combines aspects of both of these by employing a heterofunctional dicarboxylic and dipyridyl ligand, 2,5-di(pyridin-4-yl)terephthalic acid (H2L). The reaction of H2L with zinc(ii) produces a non-interpenetrated 3D coordination polymer [ZnL(H2O)]n. This journal is
A regioselectively 1,1′,3,3′-tetrazincated ferrocene complex displaying core and peripheral reactivity
Armstrong, David R.,Clegg, William,Hevia, Eva,Honeyman, Gordon W.,Kennedy, Alan R.,McLellan, Ross,Mulvey, Robert E.,Orr, Samantha A.,Parkinson, John A.,Ramsay, Donna L.,Robertson, Stuart D.,Towie, Stephen
, p. 6510 - 6520 (2020/07/15)
Regioselective 1,1′,3,3′-tetrazincation [C-H to C-Zn(tBu)] of ferrocene has been achieved by reaction of a fourfold excess of di-t-butylzinc (tBu2Zn) with sodium 2,2,6,6-tetramethylpiperidide (NaTMP) in hexane solution manifested in the trimetallic iron-sodium-zinc complex [Na4(TMP)4Zn4(tBu)4{(C5H3)2Fe}], 1. X-ray crystallographic studies supported by DFT modelling reveal the structure to be an open inverse crown in which two [Na(TMP)Zn(tBu)Na(TMP)Zn(tBu)]2+ cationic units surround a {(C5H3)2Fe}4- tetraanion. Detailed C6D6 NMR studies have assigned the plethora of 1H and 13C chemical shifts of this complex. It exists in a major form in which capping and bridging TMP groups interchange, as well as a minor form that appears to be an intermediate in this complicated exchange phenomenon. Investigation of 1 has uncovered two distinct reactivities. Two of its peripheral t-butyl carbanions formally deprotonate toluene at the lateral methyl group to generate benzyl ligands that replace these carbanions in [Na4(TMP)4Zn4(tBu)2(CH2Ph)2{(C5H3)2Fe}], 2, which retains its tetrazincated ferrocenyl core. Benzyl-Na π-arene interactions are a notable feature of 2. In contrast, reaction with pyridine affords the crystalline product {[Na·4py][Zn(py?)2(tBu)·py]}∞, 3, where py is neutral pyridine (C5H5N) and py? is the anion (4-C5H4N), a rare example of pyridine deprotonated/metallated at the 4-position. This ferrocene-free complex appears to be a product of core reactivity in that the core-positioned ferrocenyl anions of 1, in company with TMP anions, have formally deprotonated the heterocycle.
Direct Transformation of Arylamines to Aryl Halides via Sodium Nitrite and N-Halosuccinimide
Mukhopadhyay, Sushobhan,Batra, Sanjay
supporting information, p. 14622 - 14626 (2018/09/21)
A one-pot universal approach for transforming arylamines to aryl halides via reaction with sodium nitrite (NaNO2) and N-halosuccinimide (NXS) in DMF at room temperature under metal- and acid-free condition is described. This new protocol that is complementary to the Sandmeyer reaction, is suggested to involve the in situ generation of nitryl halide induce nitrosylation of aryl amine to form the diazo intermediate which is halogenated to furnish the aryl halide.
DOSY NMR, X-ray Structural and Ion-Mobility Mass Spectrometric Studies on Electron-Deficient and Electron-Rich M6L4 Coordination Cages
Bonakdarzadeh, Pia,Topi?, Filip,Kalenius, Elina,Bhowmik, Sandip,Sato, Sota,Groessl, Michael,Knochenmuss, Richard,Rissanen, Kari
supporting information, p. 6055 - 6061 (2015/06/25)
A novel modular approach to electron-deficient and electron-rich M6L4 cages is presented. From the same starting compound, via a minor modulation of the synthesis route, two C3-symmetric ligands L1 and L2 with different electronic properties are obtained in good yield. The trifluoro-triethynylbenzene-based ligand L1 is more electron-deficient than the well-known 2,4,6-tri(4-pyridyl)-1,3,5-triazine, while the trimethoxy-triethynylbenzene-based ligand L2 is more electron-rich than the corresponding benzene analogue. Complexation of the ligands with cis-protected square-planar [(dppp)Pt(OTf)2] or [(dppp)Pd(OTf)2] corner-complexes yields two electron-deficient (1a and 1b) and two electron-rich (2a and 2b) M6L4 cages. The single crystal X-ray diffraction study of 1a and 2a confirms the expected octahedral shape with a ca. 2000 ?3 cavity and ca. 11 ? wide apertures. The crystallographically determined diameters of 1a and 2a are 3.7 and 3.6 nm, respectively. The hydrodynamic diameters obtained from the DOSY NMR in CDCl3:CD3OD (4:1), and diameters calculated from collision cross sections (CCS) acquired by ion-mobility mass spectrometry (IM-MS) were for all four cages similar. In solution, the cage structures have diameters between 3.3 to 3.6 nm, while in the gas phase the corresponding diameters varied between 3.4 to 3.6 nm. In addition to the structural information the relative stabilities of the Pt6L4 and Pd6L4 cages were studied in the gas phase by collision-induced dissociation (CID) experiments, and the photophysical properties of the ligands L1 and L2 and cages 1a, 1b, 2a, and 2b were studied by UV-vis and fluorescence spectroscopy.
Alkali-metal mediated zincation of N-heterocyclic substrates using the lithium zincate complex, (THF)Li(TMP)Zn(tBu)2 and applications in in situ cross coupling reactions
Blair, Victoria L.,Blakemore, David C.,Hay, Duncan,Hevia, Eva,Pryde, David C.
supporting information; experimental part, p. 4590 - 4594 (2011/09/30)
This study investigates the ability of the mixed-metal reagent [Li(TMP)Zn(tBu)2] 1 to promote direct Zn-H exchange reactions (zincations) of a wide range of N-heterocyclic molecules. The generated metallated intermediates from these reactions are intercepted with I2 and some of them are also employed as precursors in Pd-catalysed Negishi cross-coupling applications. A comparison with recent precedents in metallation chemistry reveals that for some of these heterocycles, 1 allows improved conversions, under milder conditions and in certain cases, even gives unique regioselectivities.
Synthesis of dihydroindolizines for potential photoinduced work function alteration
Bartucci, Matthew A.,Wierzbicki, Patrycja M.,Gwengo, Chengeto,Shajan, Sunny,Hussain, Syed H.,Ciszek, Jacob W.
supporting information; experimental part, p. 6839 - 6842 (2011/03/18)
Seeking to immobilize photochromophores on metallic surfaces, we have synthesized four molecules which contain both a photoresponsive dihydroindolizine (DHI) core and a sulfur containing moiety, which allow for their assembly onto gold substrates. Sonogashira, Suzuki, or Ullmann couplings are employed to generate pyridines with pendant thioacetates (or disulfides). The pyridines are condensed with spiro[2-cyclopropene-1, 9′-[9H]fluorene]- 2, 3-dimethyl ester affording the targeted DHIs.
Conjugate addition of 2- and 4-pyridylcuprates: An expeditious asymmetric synthesis of natural (-)-evoninic acid
Spivey, Alan C.,Shukla, Lena,Hayler, Judy F.
, p. 891 - 894 (2007/10/03)
(Chemical Equation Presented) The scope and limitations of the conjugate addition of 2- and the first 4-pyridyl Gilman homocuprates to various α,β-unsaturated Michael acceptors are delineated. The conjugate addition of the cuprate of 2-bromo-3-methylpyridine to (E)-methyl crotonate then diastereoselective enolate alkylation and lipase-mediated enantioselective ester hydrolysis have enabled an efficient four-step first asymmetric synthesis of the Celastraceae sesquiterpenoid esterifying ligand (-)-(1′S,2′S) -evoninic acid.
