32917-19-4Relevant academic research and scientific papers
Stereoselective Synthesis of C-Vinyl Glycosides via Palladium-Catalyzed C?H Glycosylation of Alkenes
Chen, Gong,He, Gang,Qiao, Tianjiao,Sun, Qikai,Wang, Quanquan,Zhang, Huixing
, p. 19620 - 19625 (2021/08/09)
C-vinyl glycosides are an important class of carbohydrates and pose a unique synthetic challenge. A new strategy has been developed for stereoselective synthesis of C-vinyl glycosides via Pd-catalyzed directed C?H glycosylation of alkenes with glycosyl chloride donors using an easily removable bidentate auxiliary. Both the γ C?H bond of allylamines and the δ C?H bond of homoallyl amine substrates can be glycosylated in high efficiency and with excellent regio- and stereoselectivity. The resulting C-vinyl glycosides can be further converted to a variety of C-alkyl glycosides with high stereospecificity. These reactions offer a broadly applicable method to streamline the synthesis of complex C-vinyl glycosides from easily accessible starting materials.
Pd-Catalyzed Remote Site-Selective and Stereoselective C(Alkenyl)-H Alkenylation of Unactivated Cycloalkenes
Mao, Chun-Li,Zhao, Sheng,Zang, Zhong-Lin,Xiao, Lin,Zhou, Cheng-He,He, Yun,Cai, Gui-Xin
, p. 774 - 787 (2020/01/09)
A palladium-catalyzed alkenylation involving remote δ-position C(alkenyl)-H activation of cycloalkenes reacting with electron-deficient alkenes is described. This method features excellent site selectivity and stereoselectivity to efficiently afford only E-selective highly substituted 1,3-diene derivatives with extra-ligand-free and good functional group tolerance including estrone and free N-H tryptamine under weakly alkaline conditions. Mechanistic studies suggest that picolinamide as a bidentate directing group enables the formation of unique alkenyl palladacycle intermediates.
Regioselective intramolecular Markovnikov and anti-Markovnikov hydrofunctionalization of alkenes: Via photoredox catalysis
Li, Na,Man, Yunquan,Tang, Bo,Wang, Hongyu,Wang, Kaiye,Xiang, Yanan
supporting information, p. 11426 - 11429 (2019/09/30)
Highly regioselective Markovnikov hydrofunctionalization of alkenes was successfully realized via photoredox catalysis by introducing a urea group and fine tuning the hydrogen atom transfer catalysts. The anti-Markovnikov hydroamination of alkenes was also achieved with high yields and stereoselectivities in this work.
Domino Aryne Annulation via a Nucleophilic-Ene Process
Xu, Hai,He, Jia,Shi, Jiarong,Tan, Liang,Qiu, Dachuan,Luo, Xiaohua,Li, Yang
supporting information, p. 3555 - 3559 (2018/03/21)
1,2-Benzdiyne equivalents possess the unique property that they can react with two arynophiles through iteratively generated 1,2- and 2,3-aryne intermediates. Upon rational modification on the second leaving group of these aryne precursors, a domino aryne annulation approach was developed through a nucleophilic-ene reaction sequence. Various benzo-fused N-heterocyclic frameworks were achievable under transition metal-free conditions with a broad substrate scope.
Catalytic Multisite-Selective Acetoxylation Reactions at sp2 vs sp3 C-H Bonds in Cyclic Olefins
Zang, Zhong-Lin,Zhao, Sheng,Karnakanti, Shuklachary,Liu, Cheng-Lin,Shao, Pan-Lin,He, Yun
supporting information, p. 5014 - 5017 (2016/10/14)
The first Pd-catalyzed multisite-selective acetoxylation reactions are disclosed at an unactivated alkene sp2 C-H bond versus secondary allylic sp3 C-H bond in cyclic olefins via the modulation of directing groups. The different directing groups overcome the key challenge in differentiating C-H bonds and provide a new controlling approach for site-specific C-H activation. A wide variety of substrates are readily acetoxylated under operationally simple conditions. Mechanistic studies suggest that different Pd (IV) intermediates were involved in the multisite-selective acetoxylation reactions.
Preparing method of 1-cyclohexene ethylamine
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Paragraph 0033; 0034; 0035; 0036; 0037; 0038; 0039-0056, (2016/10/31)
The invention discloses a preparing method of 1-cyclohexene ethylamine. 1-cyclohexene acetonitrile serves as a raw material for catalytic hydrogenation, a catalyst is one or two of hafnium, vanadium and niobium, the particle size of the catalyst is 10-20mm, reaction temperature is 1200-1300 DEG C, reaction pressure is 1.1-1.2MPa, a reaction stirring speed is 500 revolutions/minute, reaction time is 2.0-3.0h, under the reaction conditions, the yield of the 1-cyclohexene ethylamine is 70% or more, the method is simple in step and easy to operate, a reaction system is high in safety performance, processing cost is low, the yield is higher and economic values are better.
(2-hydroxy)ethyl-thioureas useful as modulators of alpha2B adrenergic receptors
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, (2008/06/13)
Compounds of formula (i) and of formula (ii) wherein the symbols have the meaning disclosed in the specification, specifically or selectively modulate α2B and/or α2C adrenergic receptors in preference over α2A adrenergic receptors, and as such are useful for alleviating chronic pain and allodynia and have no or only minimal cardivascular and/or sedatory activity.
Photo-Aza-Claisen Rearrangements of Cyclic Enaminones
Vogler, B.,Bayer, R.,Meller, M.,Kraus, W.,Schell, Fred M.
, p. 4165 - 4168 (2007/10/02)
Cyclic enaminoes 1-7 were prepared and photolyzed.Compounds 1-4 reacted as expected to provide aza-De Mayo products 10 and 11, whereas 5 provided enaminone 12 in a novel photo-aza-Claisen rearrangement.Compounds 6 and 7 gave photo-aza-Claisen products 13 and 16, respectively, along with aza-De Mayo product 15 and 2 + 2 cycloaddition product 17, respectively.
Photochemistry of Succinimides with a Cycloalkenylalkyl Group in the Side Chain. Competitive Norrish Type II and Paterno-Buchi Reactions
Machida, Minoru,Oda, Kazuaki,Kanaoka, Yuichi
, p. 950 - 956 (2007/10/02)
Photolysis of N-succinimides (9c-f) (m>/=2) afforded mainly azepinediones (13c-f) with ring enlargement as the Norrish type II cyclization products.In the case of m=1, spiro-azepinedione derivatives (11a, b) were obtained in addition to tricyclic nitrogen heterocycles (10a, b), the Norrish type II products.These spiro-azepinediones are probably formed via imide imide-oxetanes by the intramolecular Paterno-Buchi reaction of these succinimides in competition with the type II processes.Keywords: N-succinimide; Norrish type II reaction; oxetane formation; azepinedione; spiro compound; photochemistry.
