84184-52-1Relevant academic research and scientific papers
Synthesis of Enantioenriched 3,4-Disubstituted Chromans through Lewis Base Catalyzed Carbosulfenylation
Denmark, Scott E.,Laverny, Aragorn,Menard, Travis
, p. 14290 - 14310 (2021/11/12)
A method for the catalytic, enantioselective, carbosulfenylation of alkenes to construct 3,4-disubstituted chromans is described. Alkene activation proceeds through the intermediacy of enantioenriched, configurationally stable thiiranium ions generated from catalytic, Lewis base activation of an electrophilic sulfenylating agent. The transformation affords difficult-to-generate, enantioenriched, 3,4-disubstituted chromans in moderate to high yields and excellent enantioselectivities. A variety of substituents are compatible including electronically diverse functional groups as well as several functional handles such as aryl halides, esters, anilines, and phenols. The resulting thioether moiety is amenable to a number of functional group manipulations and transformations. Notably, the pendant sulfide was successfully cleaved to furnish a free thiol which readily provides access to most sulfur-containing functional groups which are present in natural products and pharmaceuticals.
Copper(I)-Catalyzed Allylic Substitutions with a Hydride Nucleophile
Nguyen, T. N. Thanh,Thiel, Niklas O.,Pape, Felix,Teichert, Johannes F.
supporting information, p. 2455 - 2458 (2016/06/09)
An easily accessible copper(I)/N-heterocyclic carbene (NHC) complex enables a regioselective hydride transfer to allylic bromides, an allylic reduction. The resulting aryl- and alkyl-substituted branched α-olefins, which are valuable building blocks for synthesis, are obtained in good yields and regioselectivity. A commercially available silane, (TMSO)2Si(Me)H, is employed as hydride source. This protocol offers a unified alternative to the established metal-catalyzed allylic substitutions with carbon nucleophiles, as no adaption of the catalyst to the nature of the nucleophile is required.
A novel and efficient procedure for the preparation of allylic alcohols from α,β-unsaturated carboxylic esters using LiAlH4/BnCl
Wang, Xiaolong,Li, Xiaodong,Xue, Jijun,Zhao, Yuling,Zhang, Yumei
experimental part, p. 413 - 415 (2009/05/11)
A new and efficient method for the reduction of α,β-unsaturated carboxylic esters to allylic alcohols utilizing LiAlH4/BnCl is described. Various α,β-unsaturated esters, including the coumarins bearing α,β-unsaturated lactone skeleton, can be converted smoothly into their corresponding allylic alcohols in high yields under mild conditions with short reaction times.
Ruthenium-catalyzed synthesis of allylic alcohols: Boronic acid as a hydroxide source
Bouziane, Asmae,Helou, Marion,Carboni, Bertrand,Carreaux, Francois,Demerseman, Bernard,Bruneau, Christian,Renaud, Jean-Luc
experimental part, p. 5630 - 5637 (2009/05/27)
Secondary allylic alcohols were synthesized from linear allylic halides or carbonates using a catalytic amount of a ruthenium complex in the presence of boronic acid. The effects of solvent, base, ruthenium precursor, and boronic acid were fully explored, and the scope of the reaction was extended to various sub-strates. We also describe a preliminary investigation towards an enantioselective process.
Chemoenzymatic total synthesis of the phytotoxic lactone herbarumin III
Nanda, Samik
, p. 3661 - 3663 (2007/10/03)
Asymmetric total synthesis of phytotoxic nonenolide herbarumin III was accomplished by a chemoenzymatic approach. The main highlight of the synthesis was to fix the hydroxyl stereocenters (C7 and C9) by lipase catalyzed irreversible transesterification.
Stereoselective synthesis of (2R, 3R)- and (2S, 3S)-2-(4-hydroxyphenyl)-3-hydroxymethyl-1,4-benzodioxan-6-carbaldehyde
Gu,Chen,Jing,Pan
, p. 397 - 399 (2007/10/03)
A novel stereoselective synthetic approach to 1,4-benzodioxane lignans was reported in which (2R, 3R)- and (2D, 3S)-2-(4-hydroxyphenyl)-3-hydroxymethyl-1,4-benzodioxan-6-carbaldehyde were first synthesised.
Constrained amino acids. An approach to the synthesis of 3-substituted prolines
Waid, Philip P.,Flynn, Gary A.,Huber, Edward W.,Sabol, Jeffrey S.
, p. 4091 - 4094 (2007/10/03)
The synthesis of diastereomeric substituted proline peptidomimetics as conformationally restricted tyrosine derivatives 1a,b has been accomplished utilizing the intramolecular hydroboration-cycloalkylation of azido-olefins 7a,b as the key step.
A Study on Horseradish Peroxidase-mediated Coupling of Phenolesters, Directed to Synthesis of Lythraceae Alkaloids
Krawczyk, Andrzej R.,Lipkowska, Ewa,Wrobel, Jerzy T.
, p. 115 - 122 (2007/10/02)
Phenolesters 2, 6 and 13 were used as substrates for the oxidative coupling by means of horseradish peroxidase/hydrogen peroxide system (HRPO/H2O2).The results are discussed from the viewpoint of the possible applications of phenolesters as model compounds for the synthesis of Lythraceae alkaloids.
THE TOTAL SYNTHESIS OF (+/-)-LATIFINE
Takano, Seiichi,Akiyama, Masashi,Ogasawara, Kunio
, p. 505 - 506 (2007/10/02)
Latifine, a novel phenolic isoquinoline base from Crinum latifolium L. (Amaryllidaceae), has been synthesized.
Pyrazolopyrimidine Ribonucleosides as Anticoccidials. 3. Synthesis and Activity of Some Nucleosides of 4-pyrazolopyrimidines
Rideout, Janet L.,Krenitsky, Thomas A.,Chao, Esther Y.,Elion, Gertrude B.,Williams, Raymond B.,Latter, Victoria S.
, p. 1489 - 1494 (2007/10/02)
Ribonucleosides of 4-(alkylthio)-1H-pyrazolopyrimidines have been shown to be useful anticoccidial agents .In that study, the unsaturated 4-allylthio and 4-crotylthio derivatives (19 and 20) were shown to be more active in vivo against Eimeria tenella than their saturated congeners; therefore, some unsaturated (arylalkyl)thio derivatives were synthesized and investigated as anticoccidial agents.The novel compounds in this study (2 to 18) were prepared by the alkylation of 4-mercapto-1-β-D-ribofuranosyl-1H-pyrazolopyrimidine (1), which was prepared by an enzymatic method.The (E)-4-cinnamylthio derivative (2) and the 5'-monophosphate (18) were the most active compounds against E. tenella in vivo.None of the analogues with substituents in the aryl moiety (3 to 13) was more active than 2 in vivo.The geometry about the double bond was important, since the (Z)-4-cinnamylthio derivative (14) was inactive both in vitro and in vivo.The 4-(3-phenylpropynyl)thio and 4-(5-phenyl-2,4-pentadienyl)thio derivatives (15 and 16) were at least as active as 2 in vitro; however, they were less active than 2 in vivo.Compound 2 was effective in vivo against E. tenella, E. necatrix, E. maxima, and E. brunetti; these species of Eimeria were controlled when 2 was given in the diet at levels up to 100 ppm.Infections in vivo due to E. acervulina were controlled by 2 only at about 800 ppm.The broad spectrum of anticoccidial activity shown by 2 represents a significant improvement over the activities reported for related compounds .
