18438-38-5Relevant academic research and scientific papers
Photo-induced thiolate catalytic activation of inert Caryl-hetero bonds for radical borylation
K?nig, Burkhard,Wang, Hua,Wang, Shun
supporting information, p. 1653 - 1665 (2021/06/17)
Substantial effort is currently being devoted to obtaining photoredox catalysts with high redox power. Yet, it remains challenging to apply the currently established methods to the activation of bonds with high bond dissociation energy and to substrates with high reduction potentials. Herein, we introduce a novel photocatalytic strategy for the activation of inert substituted arenes for aryl borylation by using thiolate as a catalyst. This catalytic system exhibits strong reducing ability and engages non-activated Caryl–F, Caryl–X, Caryl–O, Caryl–N, and Caryl–S bonds in productive radical borylation reactions, thus expanding the available aryl radical precursor scope. Despite its high reducing power, the method has a broad substrate scope and good functional-group tolerance. Spectroscopic investigations and control experiments suggest the formation of a charge-transfer complex as the key step to activate the substrates.
Nickel-Catalyzed Reversible Functional Group Metathesis between Aryl Nitriles and Aryl Thioethers
Delcaillau, Tristan,Boehm, Philip,Morandi, Bill
supporting information, p. 3723 - 3728 (2021/04/07)
We describe a new functional group metathesis between aryl nitriles and aryl thioethers. The catalytic system nickel/dcype is essential to achieve this fully reversible transformation in good to excellent yields. Furthermore, the cyanide- and thiol-free reaction shows high functional group tolerance and great efficiency for the late-stage derivatization of commercial molecules. Finally, synthetic applications demonstrate its versatility and utility in multistep synthesis.
Carbon-sulfur bond reductive coupling from a platinum(II) thiolate complex
Niazi, Maryam,Shahsavari, Hamid R.,Haghighi, Mohsen Golbon,Halvagar, Mohammad Reza,Hatami, Samaneh,Notash, Behrouz
, p. 95073 - 95084 (2016/10/22)
The room temperature addition of electrophilic alkyl halide reagents (RX = MeI, EtI and PhCH2Br) to complex [Pt(ppy)(η1-S-Spy)(PPh3)], 1a, in which ppyH = 2-phenylpyridine and pySH = pyridine-2-thiol, resulted in a rapid carbon-sulfur (C-S) bond reductive coupling to produce alkyl sulfides and corresponding halide complexes [Pt(ppy)(PPh3)X], X = I (2a) and Br (2b). A mechanism for this C-S bond formation reaction was suggested based on 1H and 31P {1H} NMR spectroscopic analyses. In the suggested mechanism, the reaction proceeded through a binuclear intermediate complex [{Pt(ppy)(PPh3)}2(μ2-Spy)]I, 3-I, which was separately synthesized by another counter anion (PF6) and it was fully characterized by multinuclear NMR spectroscopy and single X-ray crystallography. Also, density functional theory (DFT) calculations were used to theoretically assess the structures of intermediates and transition states in this bond formation reaction.
One-Pot Two-Step Synthesis of Aryl Sulfur Compounds by Photoinduced Reactions of Thiourea Anion with Aryl Halides
Argueello, Juan E.,Schmidt, Luciana C.,Penenory, Alicia B.
, p. 4133 - 4136 (2007/10/03)
(Equation presented) The photoinduced reactions of aryl halides with the thiourea anion afford arene thiolate ions in DMSO. These species without isolation, and by a subsequent aliphatic nucleophilic substitution, S RN1 reaction, oxidation, or protonation, yield aryl methyl sulfides, diaryl sulfides, diaryl disulfides, and aryl thiols with good yields (50-80%). This is a simple and convenient approach which involves the use of the commercially available and inexpensive thiourea in a one-pot two-step process for the synthesis of aromatic sulfur compounds.
The invention of radical reactions. Part XXVII. Modified Julia synthesis of olefins using radical deoxygenation
Barton, Derek H. R.,Tachdjian, Catherine
, p. 7109 - 7120 (2007/10/02)
Xanthate derivatives of β-hydroxy sulfones react with methyl radicals generated from the photolysis of N-acetyloxy-2-thiopyridone to give the corresponding olefin. Under identical conditions a secondary alcohol is transformed into its thiopyridyl derivative.
Preparation of six membered carocycles by aryl-tellurium mediated free-radical cyclisation
Barton,Dalko,Gero
, p. 4713 - 4716 (2007/10/02)
Radical cyclisation of various telluro-compounds was examined. Olefins conjugated to an electron withdrawing group, (7, 8, 9, 10, and 11) gave high yields of the corresponding six membered products. Non-activating olefin 23 gave the corresponding thiopyridyl derivative 24 as the only product. The photolysis, using oxime 18 as radicophile for the cyclisation, proceeded slowly at room temperature, and gave only a low yield of products 19 and 20.
ipso-Substitution of a Sulphinyl or Sulphonyl Group Attached to Pyridine Rings and its Application for the Synthesis of Macrocycles
Furukawa, Naomichi,Ogawa, Satoshi,Kawai, Tsutomu,Oae, Shigeru
, p. 1839 - 1845 (2007/10/02)
A sulphinyl or sulphonyl group directly bound to the 2- or 4-position of a pyridine ring was readily displaced by several nucleophiles such as RO-, RS-, and CN- to afford the corresponding ipso-substitution products.Similarly, 2-halogeno-6-methylsulphinyl- or -methylsulphonyl-pyridines also react with nuclephiles to afford 2-halogeno-6-substituted pyridine derivatives.Thus, the leaving abilities of the leaving groups fall in the order RSO2 > RSO > Br ca.Cl >> RS (R = alkyl or benzyl).The ipso-substitution can be applied to the synthesis of 2,6-disubstituted pyridino macrocycles containing both carbon-oxygen and carbon-sulphur bridges, resulting in several new macrocycles in moderate yields.
Functionalization of Pyridine via Direct Metallation
Verbeek, Jacob,George, Albert V. E.,Jong, Robertus L. P. de,Brandsma, Lambert
, p. 257 - 258 (2007/10/02)
The isolation of mixtures of 2-, 3-, and 4-deuteriopyridine, 2-, 3-, and 4-trimethylsilylpyridine, or 2-, 3-, and 4-methylthiopyridine indicates successful metallation of pyridine with a 1:1 mixture of BuLi-ButOK in tetrahydrofuran-hexane at -100 deg C.
SELECTIVE IPSO-SUBSTITUTION IN PYRIDINE RING AND ITS APPLICATION FOR THE SYNTHESIS OF MACROCYCLES CONTAINING BOTH OXA- AND THIA-BRIDGES
Furukawa, Naomichi,Ogawa, Satoshi,Kawai, Tsutomu,Oae, Shigeru
, p. 3243 - 3246 (2007/10/02)
Both the sulfinyl and sulfonyl groups directly bound to 2 or 4 position in pyridine were readily displaced by several nucleophiles such as RO(1-) and RS(1-) .The facility of the leaving groups is RSO2 = RSO > Br = Cl >> RS (R:alkyl or benzyl).The ipso-substitution could be applied for the synthesis of new type of 2,6-disubstituted macrocycles containing both carbon-oxygen and carbon-sulfur bridges in moderate yields.
