Synthesis and properties of new types of sulfoxide‐ or sulfone‐bridged lewis acids

Ohba, Yusuke; K, Ito; Nagasawa, Tomomi; Sakurai, Shinichi

doi:10.1002/jhet.5570370508

Cited by 7 publications

(4 citation statements)

References 19 publications

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“…SO LH 2 can be prepared from S LH 2 by oxidation with 3-chloroperoxybenzoic acid (1 equiv) at 0 8C, while the synthesis of SO 2 LH 2 requires more forcing conditions (30 % H 2 O 2 , 40 equiv, glacial acetic acid, 100 8C). [10] The subsequent preparation of 2 (PPh 4 -A C H T U N G T R E N N U N G [ SO LVO 2 ]) followed the procedure described for 1: SO LH 2 was dissolved in acetonitrile and treated with PPh 4 A C H T U N G T R E N N U N G [VO 2 Cl 2 ] in the presence of NEt 3 . Workup led to pure 2, and cooling of a saturated dark violet solution of 2 in acetonitrile (that according to Figure 2 mainly contains 2 m ) led to red crystals.…”

Section: Resultsmentioning

confidence: 99%

Haloperoxidase Activity of Oxovanadium(V) Thiobisphenolates

Werncke

Limberg

Knispel

et al. 2011

Chemistry A European J

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By employing the 2,2'-thiobis(2,4-di-tert-butylphenolate) ligand ((S)L(2-)) a novel oxovanadium(V) complex, (PPh(4))(2)[(S)LV(O)(μ(2)-O)(2)V(O)(S)L] (1), was synthesised that exhibits haloperoxidase activity: on addition of H(2)O(2) a sequence of successive peroxide formation and intramolecular thioether oxidation events (sulfoxide and sulfone) led to a mixture of five products, which were all identified unambiguously, partly through an independent synthesis and characterisation. It was shown that internal thioether oxidation proceeds through peroxide formation, but the sulfoxidation of external thioether functions requires further activation of the peroxide function by protons or alkyl cations. Consistently, the employment of tBuOOH instead of H(2)O(2) led to a very active system for the catalytic sulfoxidation of thioethers.

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Section: Resultsmentioning

confidence: 99%

Haloperoxidase Activity of Oxovanadium(V) Thiobisphenolates

Werncke

Limberg

Knispel

et al. 2011

Chemistry A European J

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“…The dependence of activity upon the oxidation state of sulfur is not easy to predict on the basis of known chemistry. Ohba and co-workers, studying the Lewisacid-catalyzed rearrangement of aromatic epoxides to ketones by aluminum complexes, found that sulfoxide-, sulfone-, 11 and trisulfido-bridged 12 biphenol ligands all support high activity for this reaction.…”

Section: Resultsmentioning

confidence: 99%

“…1 H NMR (CDCl3), δ (ppm): 7.07-7.13 (m), 4H, Ar-H; 6.82 (d, J ) 2.4 Hz), 1H, Ar-H; 6.28 (s), 1H, OH; 2.41 (s), 6H, CH3; 1.38 (s), 9H, t-Bu; 1.13 (s), 9H, t-Bu. 13 (3-t-Butyl-2-diethylalumino-5-methylphenyl)(3-t-butyl-2-methoxy-5-methylphenyl)sulfide (11). To a solution of 2.008 g (5.4 mmol) of 5a in 15 mL of dry hexanes was added dropwise a hexane solution of trimethylaluminum (5.4 mmol) in hexane (8 mL).…”

Section: 4-di-t-butyl-6-[(35-di-t-butyl-2-methoxyphenyl)thio]phenol (5d)mentioning

confidence: 99%

Ethylene Oxide Polymerization Catalyzed by Aluminum Complexes of Sulfur-Bridged Polyphenols

et al. 2004

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The products derived from the reaction of sterically hindered sulfur-bridged bisphenols with aluminum trialkyls enable the efficient polymerization of ethylene oxide. The activity of the catalyst is largely determined by the structure of the bisphenol ligand and the size of the aluminum alkyl groups. Bonds of sulfur to aluminum are a common feature of the solid-state structures of compounds examined to this point. In solution, precatalysts of the formula (3-t-Bu-5-Me-2-OAlEt2−C6H2)2S are fluxional, and two processes appear to contribute to the equilibration of all ethyl substituents. The addition of a hindered monomer, 1,2-epoxyhexane, causes the initial formation of solvation complexes with the aluminum precatalysts and effects the disproportionation of the initial dialuminum complex of the bisphenol. One of the polymer end groups appears to be easily replaced by a halide atom during acid workup.

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“…The combined organic layer was washed with brine (50 mL × 2), dried over MgSO 4 , and evaporated. The residue was crystallized from hexane to give dibromide 7 as colorless crystals (7.00 g, 95%), mp 110–111 °C (lit . 110–112 °C); IR (KBr) 3401, 3294, 2964 cm –1 ; 1 H NMR (400 MHz) δ 1.23 (s, 18H), 6.53 (s, 2H), 7.30 (d, 2H, J = 2.3 Hz), 7.44 (d, 2H, J = 2.3 Hz); 13 C NMR (100 MHz) δ 31.2, 34.3, 109.5, 119.8, 130.6, 130.8, 145.4, 150.0; HRMS (FAB) calcd for C 20 H 24 Br 2 O 2 S M + 487.9843, found 487.9844.…”

Section: Experimental Sectionmentioning

confidence: 99%

Design and Synthesis of Open-Chain Hosts Having a Partial Structure of p-tert-Butylthiacalixarene

et al. 2018

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The development of separation materials for hard-to-separate molecular mixtures is highly desired from environmental and economic perspectives. Although the crystal of p-tert-butylthiacalix[4]arene exhibits high guest selectivity in inclusion from a mixture of molecules with similar sizes and shapes, it cannot include molecules larger than its calix cavity. To extend its guest inclusivity, we designed and synthesized an open-chain host, [3,3'-thiobis(5-tert-butyl-2-hydroxybenzene)-1,1'-diyl]diacetic acid (4). The competitive inclusion among toluidine isomers using compound 4 gave inclusion crystals containing the p-isomer in 1:1 (host/guest) ratio, with lesser amounts of other isomers and/or solvent molecules. The isomer selectivity varied between 66% and 97% depending on the solvent employed. X-ray analysis of inclusion crystals 4·p-toluidine·MeCN and 4·p-toluidine·(o-toluidine) revealed that compound 4 includes p-toluidine by forming macrocyclic 2:2 inclusion complex(es) and that its higher-order structure has vacant spaces, in which molecules other than p-toluidine are included. Compound 4 was then transformed into monopropyl ester 5 to fill the vacant spaces with propyl moieties. Compound 5 included p-toluidine with high selectivity (∼96%) without the coinclusion of other molecules, regardless of the solvent employed.

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Synthesis and properties of new types of sulfoxide‐ or sulfone‐bridged lewis acids

Cited by 7 publications

References 19 publications

Haloperoxidase Activity of Oxovanadium(V) Thiobisphenolates

Haloperoxidase Activity of Oxovanadium(V) Thiobisphenolates

Ethylene Oxide Polymerization Catalyzed by Aluminum Complexes of Sulfur-Bridged Polyphenols

Design and Synthesis of Open-Chain Hosts Having a Partial Structure of p-tert-Butylthiacalixarene

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