The Experts below are selected from a list of 219 Experts worldwide ranked by ideXlab platform
Narshinha P. Argade - One of the best experts on this subject based on the ideXlab platform.
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amano ps catalysed enantioselective acylation of α methyl 1 3 benzodioxole 5 ethanol an efficient resolution of chiral intermediates of the remarkable antiepileptic drug candidate talampanel
Tetrahedron-asymmetry, 2003Co-Authors: Srinivasan Easwar, Narshinha P. ArgadeAbstract:Abstract ( S )-(+)-α-Methyl-1,3-benzodioxole-5-ethanol 5 is a chiral building block in the synthesis of the future drug (−)-talampanel 1 . Amano PS-induced enantioselective acylation of (±)- 3 at 50°C using vinyl acetate as acyl donor furnished (+)- 5 in 53% yield and 80% e.e., and the corresponding acetyl derivative (−)-( R )-α-methyl-1,3-benzodioxole-5-ethyl acetate 6 in 44% yield and 96% e.e. The base-catalysed methanolysis of (−)- 6 followed by Mitsunobu inversion and subsequent methanolysis of the product, (+)- 8 also gave the desired (+)- 5 in 38% overall yield (four steps) and 96% e.e.
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Amano PS-catalysed enantioselective acylation of (±)-α-methyl-1,3-benzodioxole-5-ethanol: an efficient resolution of chiral intermediates of the remarkable antiepileptic drug candidate, (−)-talampanel
Tetrahedron: Asymmetry, 2003Co-Authors: Srinivasan Easwar, Narshinha P. ArgadeAbstract:Abstract ( S )-(+)-α-Methyl-1,3-benzodioxole-5-ethanol 5 is a chiral building block in the synthesis of the future drug (−)-talampanel 1 . Amano PS-induced enantioselective acylation of (±)- 3 at 50°C using vinyl acetate as acyl donor furnished (+)- 5 in 53% yield and 80% e.e., and the corresponding acetyl derivative (−)-( R )-α-methyl-1,3-benzodioxole-5-ethyl acetate 6 in 44% yield and 96% e.e. The base-catalysed methanolysis of (−)- 6 followed by Mitsunobu inversion and subsequent methanolysis of the product, (+)- 8 also gave the desired (+)- 5 in 38% overall yield (four steps) and 96% e.e.
Seiichi Nakahama - One of the best experts on this subject based on the ideXlab platform.
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protection and polymerization of functional monomers 24 anionic living polymerizations of 5 vinyl and 4 vinyl 1 3 Benzodioxoles
Macromolecules, 1995Co-Authors: Takashi Ishizone, Akihoko Mochizuki, Akira Hirao, Seiichi NakahamaAbstract:Anionic polymerizations of 5-vinyl-1,3-benzodioxole (1) and 4-vinyl-1,3-benzodioxole (2) were carried out in tetrahydrofuran at -78 o C with oligo(α-methylstyryl)dilithium and -dipotassium. The vinyl polymerizations of 1 and 2 proceeded quantitatively within 30 min. The resulting polymers had predicted molecular weights and narrow molecular weight distributions (M w /M n <1.1), indicating the living character of the polymerization systems. These living polymers were however found not to be completely stable either for a long time (24 h) or at an elevated temperature (-30 o C). Well-defined block copolymers, poly(1-b-styrene-b-1), poly(styrene-b-1-b-styrene), and poly(styrene-b-2), were successfully synthesized by the sequential polymerizations. The methylenedioxy linkage of the acetal moiety of poly(1) was completely cleaved with boron tribromide-dimethyl sulfide complex in 1,2-dichloroethane to give the unstable poly(4-vinylcatechol)
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Protection and Polymerization of Functional Monomers. 24. Anionic Living Polymerizations of 5-Vinyl- and 4-Vinyl-1,3-Benzodioxoles
Macromolecules, 1995Co-Authors: Takashi Ishizone, Akihoko Mochizuki, Akira Hirao, Seiichi NakahamaAbstract:Anionic polymerizations of 5-vinyl-1,3-benzodioxole (1) and 4-vinyl-1,3-benzodioxole (2) were carried out in tetrahydrofuran at -78 o C with oligo(α-methylstyryl)dilithium and -dipotassium. The vinyl polymerizations of 1 and 2 proceeded quantitatively within 30 min. The resulting polymers had predicted molecular weights and narrow molecular weight distributions (M w /M n
Srinivasan Easwar - One of the best experts on this subject based on the ideXlab platform.
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amano ps catalysed enantioselective acylation of α methyl 1 3 benzodioxole 5 ethanol an efficient resolution of chiral intermediates of the remarkable antiepileptic drug candidate talampanel
Tetrahedron-asymmetry, 2003Co-Authors: Srinivasan Easwar, Narshinha P. ArgadeAbstract:Abstract ( S )-(+)-α-Methyl-1,3-benzodioxole-5-ethanol 5 is a chiral building block in the synthesis of the future drug (−)-talampanel 1 . Amano PS-induced enantioselective acylation of (±)- 3 at 50°C using vinyl acetate as acyl donor furnished (+)- 5 in 53% yield and 80% e.e., and the corresponding acetyl derivative (−)-( R )-α-methyl-1,3-benzodioxole-5-ethyl acetate 6 in 44% yield and 96% e.e. The base-catalysed methanolysis of (−)- 6 followed by Mitsunobu inversion and subsequent methanolysis of the product, (+)- 8 also gave the desired (+)- 5 in 38% overall yield (four steps) and 96% e.e.
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Amano PS-catalysed enantioselective acylation of (±)-α-methyl-1,3-benzodioxole-5-ethanol: an efficient resolution of chiral intermediates of the remarkable antiepileptic drug candidate, (−)-talampanel
Tetrahedron: Asymmetry, 2003Co-Authors: Srinivasan Easwar, Narshinha P. ArgadeAbstract:Abstract ( S )-(+)-α-Methyl-1,3-benzodioxole-5-ethanol 5 is a chiral building block in the synthesis of the future drug (−)-talampanel 1 . Amano PS-induced enantioselective acylation of (±)- 3 at 50°C using vinyl acetate as acyl donor furnished (+)- 5 in 53% yield and 80% e.e., and the corresponding acetyl derivative (−)-( R )-α-methyl-1,3-benzodioxole-5-ethyl acetate 6 in 44% yield and 96% e.e. The base-catalysed methanolysis of (−)- 6 followed by Mitsunobu inversion and subsequent methanolysis of the product, (+)- 8 also gave the desired (+)- 5 in 38% overall yield (four steps) and 96% e.e.
Takashi Ishizone - One of the best experts on this subject based on the ideXlab platform.
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protection and polymerization of functional monomers 24 anionic living polymerizations of 5 vinyl and 4 vinyl 1 3 Benzodioxoles
Macromolecules, 1995Co-Authors: Takashi Ishizone, Akihoko Mochizuki, Akira Hirao, Seiichi NakahamaAbstract:Anionic polymerizations of 5-vinyl-1,3-benzodioxole (1) and 4-vinyl-1,3-benzodioxole (2) were carried out in tetrahydrofuran at -78 o C with oligo(α-methylstyryl)dilithium and -dipotassium. The vinyl polymerizations of 1 and 2 proceeded quantitatively within 30 min. The resulting polymers had predicted molecular weights and narrow molecular weight distributions (M w /M n <1.1), indicating the living character of the polymerization systems. These living polymers were however found not to be completely stable either for a long time (24 h) or at an elevated temperature (-30 o C). Well-defined block copolymers, poly(1-b-styrene-b-1), poly(styrene-b-1-b-styrene), and poly(styrene-b-2), were successfully synthesized by the sequential polymerizations. The methylenedioxy linkage of the acetal moiety of poly(1) was completely cleaved with boron tribromide-dimethyl sulfide complex in 1,2-dichloroethane to give the unstable poly(4-vinylcatechol)
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Protection and Polymerization of Functional Monomers. 24. Anionic Living Polymerizations of 5-Vinyl- and 4-Vinyl-1,3-Benzodioxoles
Macromolecules, 1995Co-Authors: Takashi Ishizone, Akihoko Mochizuki, Akira Hirao, Seiichi NakahamaAbstract:Anionic polymerizations of 5-vinyl-1,3-benzodioxole (1) and 4-vinyl-1,3-benzodioxole (2) were carried out in tetrahydrofuran at -78 o C with oligo(α-methylstyryl)dilithium and -dipotassium. The vinyl polymerizations of 1 and 2 proceeded quantitatively within 30 min. The resulting polymers had predicted molecular weights and narrow molecular weight distributions (M w /M n
Chi Liu - One of the best experts on this subject based on the ideXlab platform.
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two c o bond formations on a carbenic carbon palladium catalyzed coupling of n tosylhydrazones and benzo 1 2 quinones to construct Benzodioxoles
Organic Letters, 2018Co-Authors: Huanfeng Jiang, Fulin Chen, Chuanle Zhu, Rui Zhu, Hao Zeng, Chi LiuAbstract:A novel and efficient method for the formation of two C–O bonds on a carbenic carbon is reported. This palladium-catalyzed coupling of N-tosylhydrazones and benzo-1,2-quinones were involved the process of carbonyl ylides generation, aromatization, and intramolecular nucleophilic addition, delivering various useful Benzodioxoles in high yields.
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Two C–O Bond Formations on a Carbenic Carbon: Palladium-Catalyzed Coupling of N‑Tosylhydrazones and Benzo-1,2-quinones To Construct Benzodioxoles
2018Co-Authors: Huanfeng Jiang, Fulin Chen, Chuanle Zhu, Rui Zhu, Hao Zeng, Chi LiuAbstract:A novel and efficient method for the formation of two C–O bonds on a carbenic carbon is reported. This palladium-catalyzed coupling of N-tosylhydrazones and benzo-1,2-quinones were involved the process of carbonyl ylides generation, aromatization, and intramolecular nucleophilic addition, delivering various useful Benzodioxoles in high yields