- A Domino Strategy for the Synthesis of 2H-Pyrans from Propargyl Vinyl Ethers
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Stable monocyclic 2H-pyrans are synthesized from readily available tertiary propargyl vinyl ethers via a metal-free all-pericyclic domino manifold involving a sequential propargyl Claisen rearrangement/[1,3]H-shift/oxa-6π electrocyclization set of reactions. The wide scope of this protocol is exemplified by the synthesis of 21 different 2H-pyrans incorporating a varied substitution pattern at the ring.
- Tejedor, David,Delgado-Hernández, Samuel,Diana-Rivero, Raquel,Díaz-Díaz, Abián,García-Tellado, Fernando
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Read Online
- BTK Inhibitors and uses thereof
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The invention discloses a bruton's tyrosine kinase (BTK) inhibitor and use thereof. Specifically, the invention provides heteroaromatic compounds or stereoisomers, geometrical isomers, tautomers, racemates, nitrogen oxides, hydrates, solvates, metabolites and pharmaceutically acceptable salts or prodrugs thereof, and pharmaceutical compositions containing the heteroaromatic compounds; the invention also discloses use of the heteroaromatic compounds or the pharmaceutical compositions containing the heteroaromatic compounds in preparation of medicines; the medicines can be used for treating autoimmune diseases, inflammatory diseases or proliferative diseases.
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Paragraph 0561-0566
(2020/05/02)
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- Enantioselective Construction of Quaternary Stereogenic Centers by the Addition of an Acyl Anion Equivalent to 1,3-Dienes
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We report the enantioselective formation of quaternary stereogenic centers by the intermolecular addition of malononitrile, an acyl anion equivalent, and related pronucleophiles to several 1,3-disubstituted acyclic 1,3-dienes in the presence of a Pd-PHOX catalyst. Products are obtained in up to 88% yield and 99:1 er and in most cases are formed as a single regioisomer. The products' malononitrile unit undergoes oxidative functionalization to afford β,γ-unsaturated carbonyls bearing internal olefins and α-quaternary stereogenic centers.
- Adamson, Nathan J.,Malcolmson, Steven J.,Nguyen, Andrew L.,Park, Sangjune,Zhou, Pengfei
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supporting information
(2020/03/04)
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- Neighboring Carbonyl Group Assisted Oxyacetoxylation of Propargylic Carboxylates with Retention of Chirality under Metal Free Condition
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A metal-free oxyacetoxylation method of primary, secondary and tertiary propargylic carboxylates with retention of chirality was presented. The reaction proceeds through the intramolecular nucleophilic attack of the neighboring carbonyl group on an alkynyliodonium intermediate. The process is general with broad substrate scope and is amenable for application to a variety of propargyl carboxylates including those obtained from natural products. Insight into the mechanistic pathway by isotopic labelling (using H2O18 and D2O) and controlled experiments confirmed. (Figure presented.).
- Pradhan, Tapas R.,Mohapatra, Debendra K.
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supporting information
p. 3605 - 3611
(2019/07/04)
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- Iron-Catalyzed Dehydrative Alkylation of Propargyl Alcohol with Alkyl Peroxides to Form Substituted 1,3-Enynes
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This paper reports a new method for the generation of substituted 1,3-enynes, whose synthesis by other methods could be a challenge. The dehydrative decarboxylative cascade coupling reaction of propargyl alcohol with alkyl peroxides is enabled by an iron catalyst and alkylating reagents. Primary, secondary, and tertiary alkyl groups can be introduced into 1,3-enynes, affording various substituted 1,3-enynes in moderate to good yields. Mechanistic studies suggest the involvement of a radical-polar crossover pathway.
- Ye, Changqing,Qian, Bo,Li, Yajun,Su, Min,Li, Daliang,Bao, Hongli
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supporting information
p. 3202 - 3205
(2018/06/11)
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- Gold-Catalyzed Rearrangement of Alkynyl Donor-Acceptor Cyclopropanes to Construct Highly Functionalized Alkylidenecyclopentenes
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A gold-catalyzed 1,7-addition-cyclization-elimination cascade sequence performed on a range of alkynyl-substituted donor-acceptor-type cyclopropanes provides facile entry to highly functionalized exo-alkylidenecyclopentenes under very mild conditions. Iso
- Chen, Huiyu,Zhang, Jing,Wang, David Zhigang
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supporting information
p. 2098 - 2101
(2015/05/13)
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- Au-catalyzed formation of functionalized quinolines from 2-alkynyl arylazide derivatives
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A new method for converting 2-alkynyl arylazide derivatives into functionalized polysubstituted quinolines following a gold-catalyzed 1,3-acetoxy shift/cyclization/1,2-group shift sequence has been developed. This transformation proceeds under mild reaction conditions, is efficient, and tolerates a large variety of functional groups.
- Gronnier, Colombe,Boissonnat, Guillaume,Gagosz, Fabien
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supporting information
p. 4234 - 4237
(2013/09/12)
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- Cyclopropanation of strained alkenes by palladium-catalyzed reaction of 3-trimethylsilyl- or 3-pinacolatoboryl-1-arylallyl acetates
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The palladium-catalyzed cyclopropanation of strained alkenes with 3-trimethylsilyl- or 3-pinacolatoboryl-1-arylallyl acetate derivatives is described. This reaction gives cyclopropanation products in good to high yields with a single diastereomer, and the key step is likely to involve the formation of a palladacyclobutene complex from the α-trimethylsilyl- or α-pinacolatoboryl-σ-allylpalladium complex. Copyright
- Horino, Yoshikazu,Homura, Naoki,Inoue, Kana,Yoshikawa, Saori
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supporting information; experimental part
p. 828 - 834
(2012/05/04)
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- Synthesis of allenes via gold-catalyzed intermolecular reaction of propargylic alcohols and aromatic compounds
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Functionalized allenes are efficiently synthesized in moderate to high yield from gold-catalyzed intermolecular reaction of propargylic alcohols and aromatic compounds. The user-friendly process could be conducted under mild reaction conditions with easily accessible starting materials.
- Xu, Cheng-Fu,Xu, Mei,Yang, Liu-Qing,Li, Chuan-Ying
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experimental part
p. 3010 - 3016
(2012/05/05)
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- Gold-catalyzed regioselective hydration of propargyl acetates assisted by a neighboring carbonyl group: Access to α-acyloxy methyl ketones and synthesis of (±)-actinopolymorphol B
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A general atom-economical approach for the synthesis of α-acyloxy methyl ketone is demonstrated through regioselective hydration of a wide range of propargyl acetates. Readily available catalyst comprising of 1% Ph 3PAuCl and 1% AgSbF6 in dioxane-H2O efficiently hydrolyzes the terminal alkynes of the propargyl acetate in the absence of acid promoters at ambient temperature within a short time. Effective regioselective hydration is facilitated by the neighboring carbonyl group as demonstrated through 18O-labeling study. Compatibility of functional moieties and tolerance to various acid-labile protecting groups are observed. The catalytic condition is also suitable to perform hydration of TMS-substituted propargyl acetates, even though it requires prolonged reaction time for completion. Stereointegrity of the propargylic acetate is preserved during the hydration. The robustness of the system is successfully demonstrated through gram scale preparation of the product in nearly quantitative yield. The common α-acyloxy methyl ketone is transformed to 1,2-diol and 1,2-amino alcohol derivatives. Synthesis of actinopolymorphol B is achieved for the first time involving hydration of the propargyl acetate as the key step.
- Ghosh, Nayan,Nayak, Sanatan,Sahoo, Akhila K.
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supporting information; experimental part
p. 500 - 511
(2011/04/17)
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- A convenient method for the aromatic amino-claisen rearrangement of N-(1,1-disubstituted-allyl)anilines
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N-(1,1-Disubstituted-allyl)anilines are rearranged cleanly and in high yield to 2-(3,3-disubstituted-allyl)anilines using a catalytic amount of p-toluenesulfonic acid in acetonitrile/water (10:1).
- Cooper,Lucas,Taylor,Ward,Williamson
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p. 621 - 625
(2007/10/03)
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- Generation and reactions of alkynylsamariums
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Three methods have been developed for generating alkynylsamariums: (1) reduction of iodoalkynes with SmI2 in the presence of HMPA, (2) deprotonation at the terminal position of 1-alkynes either by tetrahydrofurylsamarium generated by PhI and Sm
- Kunishima, Munetaka,Nakata, Daisuke,Tanaka, Shinobu,Hioki, Kazuhito,Tani, Shohei
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p. 9927 - 9935
(2007/10/03)
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- DEHYDRATION OF TERITARY ARYL TRIMETHYLSILYL ACETYLENIC ALCOHOLS
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The dehydration of tertiary aryl acetylenic alcohols with a free and with a protected ethynyl hydrogen was investigated.The introduction of a trimethylsilyl protecting group leads to a considerable acceleration of the dehydration process and a rise in the
- Bychkova, N. A.,Zotchik, N. V.,Rubtsov, I. A.
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p. 1400 - 1404
(2007/10/02)
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