69045-79-0Relevant articles and documents
Photoinduced Acetylation of Anilines under Aqueous and Catalyst-Free Conditions
Yang, Yu-Ming,Yan, Wei,Hu, Han-Wei,Luo, Yimin,Tang, Zhen-Yu,Luo, Zhuangzhu
, p. 12344 - 12353 (2021/09/02)
A green and efficient visible-light induced functionalization of anilines under mild conditions has been reported. Utilizing nontoxic, cost-effective, and water-soluble diacetyl as photosensitizer and acetylating reagent, and water as the solvent, a variety of anilines were converted into the corresponding aryl ketones, iodides, and bromides. With advantages of environmentally friendly conditions, simple operation, broad substrate scope, and functional group tolerance, this reaction represents a valuable method in organic synthesis.
Metathesis-active ligands enable a catalytic functional group metathesis between aroyl chlorides and aryl iodides
Lee, Yong Ho,Morandi, Bill
, p. 1016 - 1022 (2018/09/06)
Current methods for functional group interconversion have, for the most part, relied on relatively strong driving forces which often require highly reactive reagents to generate irreversibly a desired product in high yield and selectivity. These approaches generally prevent the use of the same catalytic strategy to perform the reverse reaction. Here we describe a catalytic functional group metathesis approach to interconvert, under CO-free conditions, two synthetically important classes of electrophiles that are often employed in the preparation of pharmaceuticals and agrochemicals—aroyl chlorides (ArCOCl) and aryl iodides (ArI). Our reaction design relies on the implementation of a key reversible ligand C–P bond cleavage event, which enables a non-innocent, metathesis-active phosphine ligand to mediate a rapid aryl group transfer between the two different electrophiles. Beyond enabling a practical and safer approach to the interconversion of ArCOCl and ArI, this type of ligand non-innocence provides a blueprint for the development of a broad range of functional group metathesis reactions employing synthetically relevant aryl electrophiles.
Synthesis and Structural Characterization of Ethynylene-Bridged Bisazines Featuring Various α-Substitution
Hübscher, J?rg,Seichter, Wilhelm,Gruber, Thomas,Kortus, Jens,Weber, Edwin
, p. 1062 - 1074 (2015/08/06)
A series of bispyridines and bispyrimidines 1a, 1b, 1c, 1d, 1e showing the heterocycles attached to both ends of an ethynylene unit and being α-substituted with chloro, tert-butylthio, and methoxy groups have been synthesized via cross-coupling technique and their crystal structures studied by X-ray diffraction analysis. Supramolecular interactions of C-H···N and π···π stacking type were found to largely dominate the structures according to the compound species. A trial was given to deduce the markedly differing temperatures of melting among the compounds from special features of the crystal structures.
Nickel-Catalyzed Asymmetric Reductive Cross-Coupling between Heteroaryl Iodides and α-Chloronitriles
Kadunce, Nathaniel T.,Reisman, Sarah E.
supporting information, p. 10480 - 10483 (2015/09/28)
A Ni-catalyzed asymmetric reductive cross-coupling of heteroaryl iodides and α-chloronitriles has been developed. This method furnishes enantioenriched α,α-disubstituted nitriles from simple organohalide building blocks. The reaction tolerates a variety of heterocyclic coupling partners, including pyridines, pyrimidines, quinolines, thiophenes, and piperidines. The reaction proceeds under mild conditions at room temperature and precludes the need to pregenerate organometallic nucleophiles.
Self-assembly of heteroleptic dinuclear metallosupramolecular kites from multivalent ligands via social self-sorting
Benkh?user, Christian,Lützen, Arne
, p. 693 - 700 (2015/06/08)
A Tr?ger's base-derived racemic bis(1,10-phenanthroline) ligand (rac)-1 and a bis(2,2′-bipyridine) ligand with a central 1,3-diethynylbenzene unit 2 were synthesized. Each of these ligands acts as a multivalent entity for the binding of two copper(I) ions. Upon coordination to the metal ions these two ligands undergo selective self-assembly into heteroleptic dinuclear metallosupramolecular kites in a high-fidelity social self-sorting manner as evidenced by NMR spectroscopy and mass spectrometry.
Homoleptic zincate-promoted room-temperature halogen-metal exchange of bromopyridines
Chau, Nguyet Trang Thanh,Meyer, Maxime,Komagawa, Shinsuke,Chevallier, Floris,Fort, Yves,Uchiyama, Masanobu,Mongin, Florence,Gros, Philippe C.
experimental part, p. 12425 - 12433 (2011/01/05)
Homoleptic lithium tri- and tetraalkyl zincates were reacted with a set of bromopyridines. Efficient and chemoselective bromine-metal exchanges were realized at room temperature with a substoichiometric amount of nBu 4ZnLi2·TMEDA reagent (1/3 equiv; TMEDA=N,N,N′,N′-tetramethylethylenediamine). This reactivity contrasted with that of tBu4ZnLi2·TMEDA, which was inefficient below one equivalent. DFT calculations allowed us to rationalize the formation of N...Li stabilized polypyridyl zincates in the reaction. The one-pot difunctionalization of dibromopyridines was also realized using the reagent stoichiometrically. The direct creation of C-Zn bonds in bromopyridines enabled us to perform efficient Negishi-type cross-couplings. Mild zincation! nBu4ZnLi2·TMEDA (in substoichiometric amounts) promoted efficient and chemoselective room-temperature bromine-metal exchange of a range of bromopyridines (see scheme). DFT calculations strongly supported the formation of a stabilized tripyridylzincate, which could be reacted with electrophiles or be directly involved in palladium-catalyzed cross-coupling reactions.
Synthesis and helicate formation of a new family of binol-based bis(bipyridine) ligands
Bunzen, Jens,Bruhn, Torsten,Bringmann, Gerhard,Luetzen, Arne
scheme or table, p. 3621 - 3630 (2009/08/14)
A new family of BINOL-based bis(bipyridine) ligands 1-3 (BINOL = 2,2 -dihydroxy-1,1 -binaphthyl) was prepared in enantiomerically pure form. Whereas the coordination of zinc(ll) ions to these ligands did not result in the selective formation of a specific metallosupramolecular aggregate,1 -3 were found to undergo highly diastereoselective self-assembly to D 2-symmetric dinuclear double-stranded helicates upon coordin ation to silver(l) and copper(l) ions and to D3-symmetric dinuclear triple-stranded helicates upon coordination to iron(ll) as demonstrated by mass spectrometry and by NMR and CD spectroscopy in combination with quantum chemical calculations.
Surprising substituent effects on the self-assembly of helicates from bis(bipyridyl) BINOL ligands
Bunzen, Jens,Hovorka, Rainer,Luetzen, Arne
supporting information; scheme or table, p. 5228 - 5236 (2009/12/04)
(Figure Presented) A number of different bis(bipyridyl) BINOL ligands were prepared using a convergent building block approach. These were studied with regard to their ability to undergo self-assembly to dinuclear helicates upon coordination to suitable late-transition-metal ions. Surprisingly, the substituents at the periphery of the ligand structure were found to have a marked influence on the outcome of the self-assembly processes with regard to the helicates composition, the stereoselectivity of the helicate formation, their redox reactivity, and their electronical properties as scrutinized by NMR- and CD-spectroscopic methods as well as ESI-mass spectrometric methods.
Immobilization of bis(bipyridine) BINOL ligands and their use in chiral resolution
Bunzen, Jens,Kiehne, Ulf,Benkhaeuser-Schunk, Christian,Luetzen, Arne
supporting information; scheme or table, p. 4786 - 4789 (2009/12/29)
An enantlomerlcally pure bls(blpyrldlne) BINOL ligand was synthesized which was functionalized with an Iodine substituent In Its periphery. Using this halogen function, the ligand was Immobilized on a commercially available polystyrene gel via Suzuki cross-coupling. The functlonallzed gel was found to be effective In the chiral resolution of similar bis(blpyrldlne) ligands based on a Troeger's base core.
The influence of different spacer lengths on the selectivity of self-assembly processes of bis(bipyridine)-BINOL helicates
Bunzen, Jens,Hapke, Marko,Luetzen, Arne
scheme or table, p. 3885 - 3894 (2010/01/18)
The synthesis and self-assembly behaviour of a series of en-antiomerically pure bis(chelating) ligands is reported. The li-gands differ in the spacer unit between a BINOL core and. two bipyridyl groups as the chelating entities and were found to undergo completely diastereoselective self-assembly to di-nuclear double-stranded helicates with silver(I) salts, as dem-onstrated by NMR and CD spectroscopy and ESI mass spec-trometry. Upon coordination to iron(II) or zinc(II) ions, however, a dramatic loss in the diastereoselectivity of the self-assembly of dinuclear triple-stranded helicates was observed, as a result: of increasing spacer length. In the case of zinc(II), the self-assembly processes were even found, to be nonselec-tive with regard to the composition of the helicates.