37471-41-3Relevant academic research and scientific papers
The Interrupted Pummerer Reaction in a Sulfoxide-Catalyzed Oxidative Coupling of 2-Naphthols
He, Zhen,Pulis, Alexander P.,Procter, David J.
supporting information, p. 7813 - 7817 (2019/05/15)
A benzothiophene S-oxide catalyst, generated in situ by sulfur oxidation with H2O2, mediates the oxidative coupling of 2-naphthols. Key to the catalytic process is the capture and inversion of reactivity of a 2-naphthol partner, using an interrupted Pummerer reaction of an unusual benzothiophene S-oxide, followed by subsequent coupling with a second partner. The new catalytic manifold has been showcased in the synthesis of the bioactive natural products, (±)-nigerone and (±)-isonigerone. Although Pummerer reactions are used widely, their application in catalysis is rare, and our approach represents a new catalytic manifold for metal-free C?C bond formation.
Preparation of Thioanisole Biscarbanion and C-H Lithiation/Annulation Reactions for the Access of Five-Membered Heterocycles
Zhu, Ranran,Liu, Zheyuan,Chen, Jie,Xiong, Xiaoyu,Wang, Yuntao,Huang, Lin,Bai, Jinshan,Dang, Yanfeng,Huang, Jianhui
, p. 3161 - 3165 (2018/06/11)
The synthesis, isolation, and X-ray structure of a thioanisole-based trilithium complex are reported. On the basis of the double-lithiation strategy, two novel synthetic methodologies have been developed under mild reaction conditions (room temperature): (1) reactions of lithiated thioanisoles with nitriles give benzoisothiazoles via a [3 + 2]-type of approach with two new bond formations and (2) formation of benzothiophenes from thioanisoles and amides through a [4 + 1] pattern forming 4 new chemical bonds.
Gold-catalyzed carbene transfer to alkynes: Access to 2,4-disubstituted furans
Kramer, Soren,Skrydstrup, Troels
supporting information; experimental part, p. 4681 - 4684 (2012/06/30)
Furans of gold: The first example of a gold-catalyzed intermolecular addition of carbon ylides to terminal alkynes is reported (see scheme; DCE=dichloroethane, Tf=trifluoromethanesulfonyl). Subsequent intramolecular trapping of the generated gold carbene completes a formal [3+2] cycloaddition, which represents a novel synthesis of 2,4-disubstituted furans. Copyright
The effects of C-S and C-Se bonds on torquoselectivity: stereoselective olefination of α-thio and α-selenoketones with ynolates
Yoshikawa, Takashi,Mori, Seiji,Shindo, Mitsuru
experimental part, p. 8832 - 8838 (2010/04/06)
Highly Z-selective olefination of acyclic α-thio and α-selenoketones with ynolates has been achieved, and the theoretical calculations of the transition states in the ring-opening of the intermediates, the β-lactone enolates, revealed that the torquoselectivity was controlled by the secondary orbital interactions between the σ orbital of the C-S bond or a lone pair orbital on the S and σ* orbitals of the breaking C-O bond, and the σ orbital of the breaking C-O bond or a lone pair orbital on the O on the ring and the σ* orbitals of the C-S bond. The synthetic applications of the resulting olefins are also shown.
A new route for generation of α-λ3-iodanyl ketones via ester exchange of (Z)-(β-acetoxyvinyl)-λ3-iodanes: Their nucleophilic substitutions with halides and sulfur and phosphorus nucleophiles
Ochiai, Masahito,Nishitani, Junichi,Nishi, Yoshio
, p. 4407 - 4413 (2007/10/03)
An efficient method for generation of α-λ3-iodanyl ketones from (Z)-(2-acetoxyvinyl)(phenyl)-λ3-iodanes was developed. The method involves ester exchange of (Z)-2-acetoxyvinyl-λ3-iodanes with methanol in the presence of triethylamine. α-λ3Iodanyl ketones react with a variety of nucleophiles such as halides, thiols, phosphines, phosphinic acids, and phosphates, under the conditions which produce α-functionalized carbonyl compounds probably via an SN2 pathway.
Elaboration of 1-benzoyltetrahydroisoquinoline derivatives employing a Pictet-Spengler cyclization with α-chloro-α-phenylthioketones. Synthesis of O-methylvelucryptine
Silveira, Claudio C,Bernardi, Carmem R.,Braga, Antonio L.,Kaufman, Teodoro S.
, p. 8947 - 8950 (2007/10/03)
The reaction of N-tosyl-β-phenethylamines with α-chloro-α-phenylthioketones, leading to 1-benzoyl- and 1-pivaloyl-tetrahydroisoquinolines under modified Pictet-Spengler conditions, is described. The synthesis of O-methylvelucryptine employing this transformation as a key step is reported.
Enantioselective synthesis of α-hydroxy thioesters via oxazaborolidine- mediated reduction of α-phenylthio enones
Berenguer, Ramon,Cavero, Marta,Garcia, Jordi,Munoz, Montse
, p. 2183 - 2186 (2007/10/03)
α-Phenylthio-α,β-alkenones (2), readily available by Pd(II)-catalysed coupling of (E)-1 phenylthio-1-tributylstannylhex-1-ene with the corresponding acid chlorides have been treated with borane in the presence of phenylglycine- or proline-derived oxazaborolidines to afford 2-phenylthio-2- alken-1-ols (3) with good to excellent enantioselectivities. Ozonolysis of 3 provides a new and efficient route to chiral α-hydroxy thioesters 4.
A novel reaction of N-phenylthiocaprolactam: The α-sulfenylation of ketones under mild conditions
Foray, Gabriela,Penenory, Alicia B.,Rossi, Roberto A.
, p. 2035 - 2038 (2007/10/03)
N-phenylthiocaprolactam (2) reacts with the enolate anions of aliphatic, aromatic or cyclic ketone 1a-e, to give the corresponding α-phenylthioketones 3a-e. This reaction proceeds with high yields of monosulphenylation (80-97%) in DMSO under mild conditions (potassium ter-butoxide, 25°C, 10 min).
Triphenylbismuthonium 2-Oxoalkylide, A Moderately Stabilized Bismuthonium Ylide: Generation and Reactions with Some Electrophiles
Matano, Yoshihiro
, p. 2703 - 2710 (2007/10/02)
Treatment of (2-oxoalkyl)triphenylbismuthonium tetrafluoroborates 3 with potassium tert-butoxide in tetrahydrofuran at -78 deg C produced triphenylbismuthonium 2-oxoalkylides 4, which readily underwent epoxidation with the aldehydes 5 to give the α,β-epoxy ketones 7 with highly trans selectivity.The ylide 4a reacted with dimedone 11, the sulfonic acid 13, the thiol 15 and the isocyanate 17 to afford the corresponding ketones 12, 14, 16 and 19 in moderate to good yields.Reaction of the ylide 4c with the α,β-unsaturated ketones 10 and 21 afforded the 1,2-dibenzoyl- and the 1,2,3-tribenzoyl- cyclopropanes 20 and 22, respectively, although the yields were low.In the presence of a catalytic amount of nitrosobenzene 23, the ylide 4a a unique decomposition to give the 2,2,7,7-tetramethyloct-4-ene-3,6-dione 24 in quantitative yield, while the reaction with the nitrile oxide 25 yielded the isoxazoline 26.In all of these reactions, triphenylbusmuthane 6 was the additional major product.
Synthesis, X-ray Structure and Reactions of (2-Oxoalkyl)triarylbismuthonium Salts
Matano, Yoshihiro,Azuma, Nagao,Suzuki, Hitomi
, p. 1739 - 1748 (2007/10/02)
Treatment of triarylbismuth difluorides 1 with silyl enol ethers 2 in the presence of boron trifluoride-diethyl ether or trimethylsilyl trifluoromethanesulfonate (triflate) gave (2-oxoalkyl)triarylbismuthonium tetrafluoroborates 3 and triflates 4 in good yields.A similar reaction of the difluorides 1 with hexamethyldisiloxane in the presence of the latter acid reagent led to the formation of oxybis(triarylbismuth) ditriflates 5.X-Ray crystallographic analyses of compounds 3a, 4a and 5a showed that the first two onium salts have a distorted tetrahedral geometry and the last, a μ-oxo type compound, has a distorted trigonal bipyramidal geometry around the bismuth centre.The stability of these bismuthonium salts may reasonably be attributed to the intramolecular coordinative interaction between the bismuth and oxygen atoms and also low nucleophilicity of the counter ions employed.The bismuthonium salt 3f readily underwent onium exchange with the phosphine 6 and the sulfide 9 to afford the corresponding phosphonium and sulfonium salts 7 and 10.The salts 3 and 4 also underwent coupling with a variety of nucleophiles such as the enolate 11, piperidine 13, the phenoxides 15, the thiolates 17, the sulfinate 19 and the halides 21 to afford the corresponding α-substituted ketones 12, 14, 16, 18, 20 and 22 in moderate to good yields, together with a good recovery of triphenylbismuthine 8.
