- Preparation method of chiral optical pure p-toluenesulfinamide
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The invention discloses a preparation method of a chiral optical pure p-toluenesulfinamide. The method includes: subjecting sodium p-tolylsulfinate and an acyl chlorination reagent to acyl chlorination to obtain p-toluene sulfinyl chloride, then reacting
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Paragraph 0014; 0041; 0055; 0056
(2018/09/13)
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- Method for synthesizing chiral optical pure para-toluene sulfenamide
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The invention discloses a method for synthesizing chiral optical pure para-toluene sulfonamide. The method comprises the following steps: ensuring that para-toluene sulfinic acid sodium salt and an acylating chlorination reagent react with each other, so
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Paragraph 0040; 0054; 0055
(2018/09/21)
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- Preparation method of chiral optical pure p-toluene sulfamide
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The invention discloses a preparation method of chiral optical pure p-toluene sulfamide. The preparation method comprises the following steps: performing acylating chlorination by using sodium p-tolylsulfinate and an acylating chlorination reagent to obta
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Paragraph 0014; 0040; 0054; 0055
(2018/10/19)
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- Asymmetric synthesis of sulfinamides using (-)-quinine as chiral auxiliary
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A process has been designed and demonstrated for the asymmetric synthesis of sulfinamides using quinine as auxiliary. A variety of chiral sulfinamides including N-alkyl sulfinamides with diverse structure were prepared in good yields and excellent enantioselectivity starting from easily available and inexpensive reagents. The auxiliary quinine could be recovered and recycled.
- Zhang, Yongda,Chitale, Sampada,Goyal, Navneet,Li, Guisheng,Han, Zhengxu S.,Shen, Sherry,Ma, Shengli,Grinberg, Nelu,Lee, Heewon,Lu, Bruce Z.,Senanayake, Chris H.
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experimental part
p. 690 - 695
(2012/02/16)
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- Enantioselective synthesis of diverse sulfinamides and sulfinylferrocenes from phenylglycine-derived chiral sulfinyl transfer agent
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A new chiral sulfinyl transfer auxiliary derived from readily available phenylglycine was developed. This auxiliary is utilized to synthesize a diverse array of alkyl- and arylsulfinamides and sulfinylferrocenes in high yields and excellent ee's. The desired products are produced in a one-pot sequence from the oxathiazolidine 2-oxide by two sequential nucleophilic additions that proceed in a stereospecific manner.
- Han, Zhengxu S.,Meyer, Angelica M.,Xu, Yibo,Zhang, Yongda,Busch, Robert,Shen, Sherry,Grinberg, Nelu,Lu, Bruce Z.,Krishnamurthy, Dhileep,Senanayake, Chris H.
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p. 5480 - 5484
(2011/08/09)
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- The 3-(3-pyridine)propionyl anchor group for protease-catalyzed resolutions: p-toluenesulfinamide and sterically hindered secondary alcohols
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Compared to an acetyl acyl group, the 3-(3-pyridine)propionyl group increases substrate binding to many proteases and substrate solubility in water, thereby increasing the rates of protease-catalyzed reactions. For example, proteases reacted up to six hundred-fold faster with the 3-(3-pyridine)propionyl ester of 1-phenylethanol than with the corresponding acetate ester. In addition, the 3-(3-pyridine)propionyl group enables a simple, mild acid extraction to separate the remaining starting material and product. To demonstrate the synthetic usefulness of this strategy, we resolved multi-gram quantities of (R)- and (S)-p-toluenesulfinamide with α-chymotrypsin and gram quantities of (R)- and (S)-2,2-dimethylcyclopentanol with subtilisin Carlsberg. The 3-(3-pyridyl)propionyl group was better for these resolutions than the corresponding acetate or dihydrocinnamate because it decreased the reaction time due to increased reactivity, decreased the reaction volume due to increased substrate solubility and enabled purification without chromatography. Molecular modeling suggests the enantioselectivity of α-chymotrypsin toward (R)-p-toluenesulfinamide is high (E = 52) because of a favorable hydrophobic interaction between the p-tolyl group of the fast-reacting (R)-enantiomer and leaving group pocket. The enantioselectivity of subtilisin Carlsberg toward (S)-2,2-dimethylcyclopentanol is high (E = 43) because the large substituent (the 2,2-dimethyl quaternary carbon) of the slow-reacting (R)-enantiomer cannot fit in the S1′ leaving group pocket.
- Savile, Christopher K.,Kazlauskas, Romas J.
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p. 1183 - 1192
(2007/10/03)
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- Subtilisin-catalyzed resolution of N-acyl arylsulfinamides
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We report the first biocatalytic route to sulfinamides (R-S(O)-NH 2), whose sulfur stereocenter makes them important chiral auxiliaries for the asymmetric synthesis of amines. Subtilisin E did not catalyze hydrolysis of N-acetyl or N-butanoyl arylsulfinamides, but did catalyze a highly enantioselective (E > 150 favoring the (R)-enantiomer) hydrolysis of N-chloroacetyl and N-dihydrocinnamoyl arylsulfinamides. Gramscale resolutions using subtilisin E overexpressed in Bacillus subtilis yielded, after recrystallization, three synthetically useful auxiliaries: (R)-p- toluenesulfinamide (42% yield, 95% ee), (R)-p-chlorobenzenesulfinamide (30% yield, 97% ee), and (R)-2,4,6-trimethylbenzenesulfinamide (30% yield, 99% ee). Molecular modeling suggests that the N-chloroacetyl and N-dihydrocinnamoyl groups mimic a phenylalanine moiety and thus bind the sulfinamide to the active site. Molecular modeling further suggests that enantioselectivity stems from a favorable hydrophobic interaction between the aryl group of the fast-reacting (R)-arylsulfinamide and the S1′ leaving group pocket in subtilisin E.
- Savile, Christopher K.,Magloire, Vladimir P.,Kazlauskas, Romas J.
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p. 2104 - 2113
(2007/10/03)
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- Cinchona alkaloid/sulfinyl chloride combinations: Enantioselective sulfinylating agents of alcohols
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We report a novel approach to asymmetric sulfinylation reactions based on a cinchona alkaloid/sulfinyl chloride combination that acts as the first asymmetric sulfinylating agents of achiral alcohols. Both enantiomers of arenesulfinates are obtained with u
- Shibata, Norio,Matsunaga, Mitsuharu,Nakagawa, Masaya,Fukuzumi, Takeo,Nakamura, Shuichi,Toru, Takeshi
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p. 1374 - 1375
(2007/10/03)
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- First application of tunable alkyl or aryl sulfinamides to the stereoselective synthesis of a chiral amine: asymmetric synthesis of (R)-didesmethylsibutramine ((R)-DDMS) using (R)-triethylmethylsulfinamide ((R)-TESA).
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A highly diastereoselective addition of i-BuLi to a triethylmethylsulfinamide derived aldimine was used as the key step in the first asymmetric synthesis of (R)-didesmethylsibutramine, a metabolite of sibutramine for the potential treatment of CNS disorders. [reaction: see text]
- Han, Zhengxu,Krishnamurthy, Dhileepkumar,Pflum, Derek,Grover, Paul,Wald, Stephen A,Senanayake, Chris H
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p. 4025 - 4028
(2007/10/03)
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- Properly designed modular asymmetric synthesis for enantiopure sulfinamide auxiliaries from N-sulfonyl-1,2,3-oxathiazolidine-2-oxide agents
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Simple and practical asymmetric synthesis of functionally differentiated aminoindanol based endo-N-sulfonyl 1,2,3-oxathiazolidine-2-oxide as sulfinyl transfer agents are developed. The importance of these new and unique sulfinyl transfer reagents are exemplified by the expedient production of several sulfinamide ligands, including either enantiomer of (R)-tert-butanesulfinamide in excellent yields and enantiopurities. Copyright
- Han, Zhengxu,Krishnamurthy, Dhileepkumar,Grover, Paul,Fang, Q. Kevin,Senanayake, Chris H.
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p. 7880 - 7881
(2007/10/03)
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