ChemInform Abstract: A One-Flask, High-Yield, Stereoselective Synthesis of Racemic endo-Brevicomin.

1984 ◽  
Vol 15 (4) ◽  
Author(s):  
T. COHEN ◽  
M. BHUPATHY
Keyword(s):  
Stereoselective Synthesis ◽  
High Yield

scholarly journals Stereoselective synthesis of 2′-modified nucleosides by using ortho-alkynyl benzoate as a gold(i)-catalyzed removable neighboring participation group

RSC Advances ◽  
2017 ◽  
Vol 7 (4) ◽  
pp. 1814-1817 ◽  
Author(s):  
Haixin Ding ◽  
Chuang Li ◽  
Yirong Zhou ◽  
Sanguo Hong ◽  
Ning Zhang ◽  
...  
Keyword(s):  
Stereoselective Synthesis ◽  
Modified Nucleosides ◽  
High Yield

ortho-Alkynyl benzoate was developed as a neighboring participation group in stereoselective synthesis of nucleosides, which could be removed using gold(i)-catalysis to afford 2′-OH nucleosides in high yield and selectivity.

NBS-promoted halosulfonylation of terminal alkynes: highly regio- and stereoselective synthesis of (E)-β-halo vinylsulfones

2014 ◽  
Vol 1 (4) ◽  
pp. 361-364 ◽  
Author(s):  
Yang Gao ◽  
Wanqing Wu ◽  
Yubing Huang ◽  
Kefan Huang ◽  
Huanfeng Jiang
Keyword(s):  
Stereoselective Synthesis ◽  
High Yield ◽  
Terminal Alkynes

An efficient NBS-promoted method for the synthesis of (E)-β-halo vinylsulfones with high yield and selectivity has been developed.

Stereoselective synthesis of multiply substituted [1,2]oxazinan-3-ones via ring-closing metathesis

2005 ◽  
Vol 83 (2) ◽  
pp. 93-103 ◽  
Author(s):  
Gennady V Shustov ◽  
Melanie K Chandler ◽  
Saul Wolfe
Keyword(s):  
Stereoselective Synthesis ◽  
High Yield ◽  
Acryloyl Chloride ◽  
Successive Reaction ◽  
Ring Closing Metathesis ◽  
Silver Triflate ◽  
Asymmetric Dihydroxylation ◽  
Single Diastereomer ◽  
Cyclic Sulfite ◽  
Hydroxy Esters

The title compounds are α-amino acids whose nitrogen atoms are enclosed within 4,5-disubstituted, six-membered cyclic hydroxamates and they are of interest as potential β-lactam surrogates. The compounds have been synthesized in the present work by functionalization of the double bonds of N-substituted 6H-[1,2]oxazin-3-ones, which are obtained upon successive reaction of the triflates of S-α-hydroxy esters with O-allylhydroxylamine and acryloyl chloride, followed by cyclization of the resulting R-α-N-acryloyl-N-allyloxyamino esters in the presence of the ring-closing metathesis (RCM) catalyst bis(tricyclohexylphosphine)benzylideneruthenium dichloride. The olefins are also accessible, but less efficiently so, by a Wittig sequence that employs bromoacetyl bromide in place of acryloyl chloride, followed successively by triphenylphosphine, silver triflate, ozonolysis, and cyclization. Asymmetric dihydroxylation of these chiral olefins affords a single diastereomer in high yield having either the αR,4S,5S- or the αR,4R,5R configuration, depending on the auxiliary. The configuration of the αR,4R,5R isomer has been confirmed by its conversion to (αR,4S,5R)-2-(α-carboxyethyl)-4-phenylacetylamino-5-hydroxy-1,2-oxazinan-3-one, whose αR,4R,5S diastereomer was previously prepared from L-ascorbic acid. With N-bromosuccinimide in aqueous dimethylformamide, a 6H-[1,2]oxazin-3-one afforded a separable 1:1 mixture of bromohydrins, which could be cyclized to epoxides or hydrogenolyzed to 5-hydroxy-1,2-oxazinan-3-ones. Key words: penicillin surrogates, asymmetric dihydroxylation, bis(tricyclohexylphosphine)benzylideneruthenium dichloride, cyclic sulfite, epoxides, azidohydrin, bromohydrin.

The Stereoselective Synthesis and the Nitrogen Interconversion Studies of 2-(tert-butoxymethyl)-1-[NT-(4-methylbenzenesulfonyl) (4-methylphenoxy) imidoyl] aziridine

2000 ◽  
Vol 2000 (4) ◽  
pp. 190-192 ◽  
Author(s):  
Hossein Abdoul Dabbagh ◽  
Ali Reza Modarresi-Alam
Keyword(s):  
Title Compound ◽  
Energy Barrier ◽  
Stereoselective Synthesis ◽  
High Yield ◽  
Allyl Ether ◽  
Free Energies ◽  
One Pot ◽  
Aziridine Ring ◽  
Nitrogen Inversion ◽  
Ring Nitrogen

One-pot synthesis of the title compound (1) is achieved from tert-butyl allyl ether (2) and the N'(4-methylbenzenesulfonyl) (4-methylphenoxy) imidoyl azide (3) in high yield. The energy barrier of nitrogen interconversion of the title compound (1) was investigated by dynamic NMR. The free energies of activation (A G‡) are 11.11 kcal/mol ( Tc = 238 K) and 11.30 kcal/mol ( Tc = 242 K) in acetone-d6 and chloroform-d, respectively, and are attributed to nitrogen inversion of aziridine ring nitrogen.

Stereoselective Synthesis of (Z)-2-Bromo-2-CF3-Vinyl Phenyl Sulfide and its Sonogashira Cross-Coupling Reaction

Synlett ◽  
2019 ◽  
Vol 30 (07) ◽  
pp. 837-840 ◽  
Author(s):  
Yui Fukuda ◽  
Takumi Kikumura ◽  
Saki Sakoda ◽  
Genki Ikeda ◽  
Yuki Nakamura ◽  
...  
Keyword(s):  
Stereoselective Synthesis ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
High Yield ◽  
Phenyl Sulfide ◽  
Cross Coupling Reaction ◽  
Wide Range ◽  
Terminal Acetylenes ◽  
Synthetic Application ◽  
Coupling Partner

A practical synthesis of (Z)-2-bromo-2-CF3-vinyl phenyl sulfide from 2-CF3-vinyl phenyl sulfide was achieved using bromine (Br2) in the presence of LiBr and LiOAc in AcOH in one flask. This method affords a stereodefined product in high yield under mild conditions. The synthetic application of the product was briefly examined, providing a wide range of Sonogashira cross-coupling products using terminal acetylenes as a coupling partner.

Convenient high yield and stereoselective synthesis of O -glycopeptides using N -α-Fmoc-Tyr/Ser[β- d -Glc(OAc) 4 ]OPfp generated in solution

2004 ◽  
Vol 45 (2) ◽  
pp. 355-358 ◽  
Author(s):  
Beechanahalli P. Gangadhar ◽  
Seetharama D.S. Jois ◽  
Ambikaipakan Balasubramaniam
Keyword(s):  
Stereoselective Synthesis ◽  
High Yield

scholarly journals Reductive conjugate addition nitro-Mannich route for the stereoselective synthesis of 1,2,3,4-tetrahydroquinoxalines

2016 ◽  
Vol 14 (35) ◽  
pp. 8270-8277 ◽  
Author(s):  
James C. Anderson ◽  
Ian B. Campbell ◽  
Sebastien Campos ◽  
Iain H. Reid ◽  
Christopher D. Rundell ◽  
...  
Keyword(s):  
Mannich Reaction ◽  
Stereoselective Synthesis ◽  
Conjugate Addition ◽  
High Yield

A reductive conjugate addition nitro-Mannich reaction controls diastereoselectivity in a rapid entry to a diverse array of 1,2,3,4-tetrahydroquinoxalines in high yield.

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