136787-49-0

Upstream product

• 88159-06-2 tert-butyl(diphenyl)(2-propynyloxy)silane 
• 107-18-6 allyl alcohol 
• 58479-61-1 tert-butylchlorodiphenylsilane 

Downstream Products

• 136787-55-8 3-(tert-Butyl-diphenyl-silanyloxymethyl)-2-methoxy-cyclobutanone 
• 136787-60-5 N-[2-(tert-Butyl-diphenyl-silanyloxymethyl)-4-oxo-cyclobutyl]-4,N-dimethyl-benzenesulfonamide 
• 151948-27-5 (2S,3aS,4S,5S)-hexahydro-2-t-butyldiphenylsilyloxymethyl-4,5-bis(methoxymethoxy)-pyrrolo[1,2-b]isoxazole 
• 186900-91-4 (3aS,3bS,5S,7R,7aR)-5-(tert-Butyl-diphenyl-silanyloxymethyl)-2,2-dimethyl-7-phenylselanylmethyl-hexahydro-1,3,6-trioxa-6a-aza-cyclopenta[a]pentalene 
• 355117-89-4 3-(tert-butyldiphenylsilyloxy)-1,2-dibromopropane 
• 292616-85-4 pent-4-ynoic acid 2-[3-(tert-butyl-diphenyl-silanyloxy)-propyl]-benzyl ester 
• 735317-36-9 (tert-butyl-diphenylsilanyloxy)acetaldehyde oxime 
• 735317-55-2 (R)-1-[(4S,5R)-3-(tert-Butyl-diphenyl-silanyloxymethyl)-4-methyl-4,5-dihydro-isoxazol-5-yl]-ethanol 
• 735317-57-4 Benzoic acid (R)-1-[(4S,5R)-3-(tert-butyl-diphenyl-silanyloxymethyl)-4-methyl-4,5-dihydro-isoxazol-5-yl]-ethyl ester 

Relevant academic research and scientific papers

An efficient and general method for the synthesis of α,ω- difunctional reduced polypropionates by Zr-catalyzed asymmetric carboalumination: Synthesis of the scyphostatin side chain

A decrease in the number of linear synthetic steps and an increase in efficiency have been realized in the synthesis of the side chain of scyphostatin. An efficient and selective synthesis of α,ω- difunctional reduced polypropionates from methyl 3-hydroxy-2-methylpropionate through the use of a Zr-catalyzed asymmetric carboalumination has been developed (see scheme, TBS = tert-butyldimethylsilyl).

Synthesis of a novel class of 1,3-oxathiolane nucleoside derivatives of T-705 and evaluation of their anti-influenza a virus and anti-HIV activity

Backgroud: T-705 (Favipiravir) is a broad spectrum antiviral agent approved for stockpiling in Japan and currently in Phase 3 testing in the United States. Against influenza, it acts as a prodrug, converted intracellularly to selectively inhibit viral RNA

Carbohydrate/DBU Cocatalyzed Alkene Diboration: Mechanistic Insight Provides Enhanced Catalytic Efficiency and Substrate Scope

A mechanistic investigation of the carbohydrate/DBU cocatalyzed enantioselective diboration of alkenes is presented. These studies provide an understanding of the origin of stereoselectivity and also reveal a strategy for enhancing reactivity and broadening the substrate scope.

Hydroheteroarylation of Unactivated Alkenes Using N-Methoxyheteroarenium Salts

We report the first reductive coupling of unactivated alkenes with N-methoxy pyridazinium, imidazolium, quinolinium, and isoquinolinium salts under hydrogen atom transfer (HAT) conditions, and an expanded scope for the coupling of alkenes with N-methoxy pyridinium salts. N-Methoxy pyridazinium, imidazolium, quinolinium, and isoquinolinium salts are accessible in 1-2 steps from the commercial arenes or arene N-oxides (25-99%). N-Methoxy imidazolium salts are accessible in three steps from commercial amines (50-85%). In total 36 discrete methoxyheteroarenium salts bearing electron-donating, electron-withdrawing, alkyl, aryl, halogen, and haloalkyl substituents were prepared (several in multigram quantities) and coupled with 38 different alkenes. The transformations proceed under neutral conditions at ambient temperature, provide monoalkylation products exclusively, and form a single alkene addition regioisomer. Preparatively useful and complementary site selectivities in the addition of secondary and tertiary radicals to pyidinium salts are documented: harder secondary radicals favor C-2 addition (2->10:1), while softer tertiary radicals favor bond formation to C-4 (4.7->29:1). A diene possessing a 1,2-disubstituted and 2,2-disubstituted alkene undergoes hydropyridylation at the latter exclusively (61%) suggesting useful site selectivities can be obtained in polyene substrates. The methoxypyridinium salts can also be employed in dehydrogenative arylation, borono-Minisci, and tandem arylation processes. Mechanistic studies support the involvement of a radical process.

COMPOUNDS FOR USE IN THE TREATMENT OF INFECTIOUS DISEASES

The present invention relates to compounds of formula (I), wherein R1, R2, R3, R4, R5 and R6 are as described herein, and their prodrugs or pharmaceutically acceptable salt, enantiomer or diastereomer thereof, and compositions including the compounds and methods of using the compounds.

(-)-Tarchonanthuslactone: Design of New Analogues, Evaluation of their Antiproliferative Activity on Cancer Cell Lines, and Preliminary Mechanistic Studies

Natural products containing the α,β-unsaturated δ-lactone skeleton have been shown to possess a variety of biological activities. The natural product (-)-tarchonanthuslactone (1) possessing this privileged scaffold is a popular synthetic target, but its biological activity remains underexplored. Herein, the total syntheses of dihydropyran-2-ones modeled on the structure of 1 were undertaken. These compounds were obtained in overall yields of 17-21 % based on the Keck asymmetric allylation reaction and were evaluated in vitro against eight different cultured human tumor cell lines. We further conducted initial investigation into the mechanism of action of selected analogues. Dihydropyran-2-one 8 [(S,E)-(6-oxo-3,6-dihydro-2H-pyran-2-yl)methyl 3-(3,4-dihydroxyphenyl)acrylate], a simplified analogue of (-)-tarchonanthuslactone (1) bearing an additional electrophilic site and a catechol system, was the most cytotoxic and selective compound against six of the eight cancer cell lines analyzed, including the pancreatic cancer cell line. Preliminary studies on the mechanism of action of compound 8 on pancreatic cancer demonstrated that apoptotic cell death takes place mediated by an increase in the level of reactive oxygen species. It appears as though compound 8, possessing two Michael acceptors and a catechol system, may be a promising scaffold for the selective killing of cancer cells, and thus, it deserves further investigation to determine its potential for cancer therapy. Fighting the big C: We describe the synthesis of a new family of analogues based on the scaffold of the natural product (-)-tarchonanthuslactone; these compounds were evaluated in vitro against tumor cell lines. We further conducted an initial investigation into the mechanism of action, including the inhibition of phosphatases and glutathione-S-transferase and the production of reactive oxygen species.

cis-Semihydrogenation of alkynes with amine borane complexes catalyzed by gold nanoparticles under mild conditions

Supported gold nanoparticles catalyze the semihydrogenation of alkynes to alkenes with ammonia borane or amine borane complexes in excellent yields and under mild conditions. Internal alkynes provide cis-alkenes, making this protocol an attractive alternative of the classical Lindlar's hydrogenation.

Pt-catalyzed enantioselective diboration of terminal alkenes with B 2(pin)2

(Chemical Equation Presented) The Pt-catalyzed enantioselective addition of bis(pinacolato)diboron to simple monosubstituted alkenes is described. This reaction occurs in the presence of a readily available chiral phosphonite ligand and is effective with a variety of terminal alkene substrates. Importantly, the reaction can operate with catalyst loadings of only 1 mol % Pt. While oxidation of the intermediate 1,2-bis(boronate) ester provides the chiral 1,2-diol as the reaction product, the intermediate may also be subjected to homologation/oxidation to furnish a chiral 1,4-diol as the reaction product.

Polyketide building blocks via diastereoselective nitrile oxide cycloadditions with homoallylic alcohols and monoprotected homoallylic diols

A modular approach to δ2-isoxazolines, latent aldol adducts and polyketide building blocks, is reported. The magnesium-mediated, hydroxyl-directed method allows for the diastereoselective access to a wide variety of masked β-hydroxy ketones, starting from readily available aliphatic and aromatic oximes, homoallylic alcohols and monoprotected homoallylic diols. The utility of the prepared δ2-isoxazolines as polyketide building blocks is demonstrated by their ready conversion into the corresponding β-hydroxy ketones. The anti-diastereoselectivity of the reaction was established by derivatization, NOE studies and comparison of known compounds. A rationale for the observed diastereoselectivity is proposed.