4949-20-6Relevant academic research and scientific papers
Diels-Alder adducts of of ortho-benzoquinones: Rearrangements and further transformations
Carlini, Rina,Higgs, Kerianne,Taylor, Nicholas,Rodrigo, Russell
, p. 805 - 816 (1997)
ortho-Benzoquinones substituted with an electron-withdrawing group (EWG = CO2Me, COSMe, COCH3, CHO) at C-3 or C-4 react as dienophiles at the C3 - C4 double bond in Diels-Alder reactions with several dienes, with predictable regiochemistry. The adducts undergo migration of the "angular" EWG substituent with concomitant aromatization to produce substituted catechols. The bicyclic products can be oxidized in situ and annelated by a further Diels-Alder reaction to yield 9,10-phenanthraquinone systems. When (2E)-2,4-pentadienol is employed as the diene in the second cycloaddition, reaction of the alcoholic hydroxyl group with one of the quinone carbonyl groups results in the production of tetracyclic lactols 22a, 22b, and 23.
Method for preparing 1,3-pentadiene from xylitol
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Paragraph 0028-0053, (2018/07/06)
The invention relates to a method for preparing 1,3-pentadiene from xylitol. The method is used for preparing 1,3-pentadiene from xylitol as a raw material and is divided into two steps of reactions:firstly, 2,4-pentadiene-1-ol formate is prepared from xylitol and formic acid through a deoxygenation and dehydration reaction and an esterification reaction without a catalyst; secondly, 1,3-pentadiene is prepared from 2,4-pentadiene-1-ol formate through a deoxygenation reaction under catalysis of a hydrogenation catalyst. The catalyst and the raw material are cheap and easily available, the preparation process is simple, an externally added hydrogen source is not needed, and higher activity and selectivity are realized in the deoxygenation and dehydration reaction of xylitol and deoxygenation reaction of 2,4-pentadiene-1-ol formate. The cheap and efficient method for synthesizing 1,3-pentadiene from xylitol as a lignocellulose-based platform chemical compound is provided.
Palladium-Promoted Neutral 1,4-Brook Rearrangement/Intramolecular Allylic Cyclization Cascade Reaction: A Strategy for the Construction of Vinyl Cyclobutanols
Zhang, Hao,Ma, Shiqiang,Yuan, Ziyun,Chen, Peng,Xie, Xingang,Wang, Xiaolei,She, Xuegong
supporting information, p. 3478 - 3481 (2017/07/15)
A cascade reaction to build vinyl cyclobutanol rings through activation of vinyl epoxides by palladium, followed by 1,4-Brook rearrangement and intramolecular cyclization with a palladium complex of the resulting carbon anion, is described. Through this cascade reaction, several highly substituted cyclobutanol substrates were achieved in good yields with high stereoselectivities.
Production of renewable 1,3-pentadiene from xylitol via formic acid-mediated deoxydehydration and palladium-catalyzed deoxygenation reactions
Sun, Ruiyan,Zheng, Mingyuan,Li, Xinsheng,Pang, Jifeng,Wang, Aiqin,Wang, Xiaodong,Zhang, Tao
supporting information, p. 638 - 642 (2017/02/26)
A two-step synthetic approach for the production of renewable 1,3-pentadiene was reported: xylitol deoxydehydration (DODH) by formic acid to 2,4-pentadien-1-ol, 1-formate (2E), followed by deoxygenation to 1,3-pentadiene over Pd/C. The overall carbon yield of 1,3-pentadiene reached 51.8% under the optimized conditions.
Regioselective Epoxidations by Cytochrome P450 3A4 Using a Theobromine Chemical Auxiliary to Predictably Produce N-Protected β- or γ-Amino Epoxides
Polic, Vanja,Cheong, Kin Jack,Hammerer, Fabien,Auclair, Karine
supporting information, p. 3983 - 3989 (2017/11/30)
N-Protected β- and γ-amino epoxides are useful chiral synthons. We report here that the enzyme cytochrome P450 3A4 can catalyze the formation of such compounds in a regio- and stereoselective manner, even in the presence of multiple double bonds or aromatic substituents. To this end, the theobromine chemical auxiliary is used not only to control the selectivity of the enzyme, but also as a masked amine, and to facilitate product recovery. Theobromine predictably directed epoxidation at the double bond of the fourth carbon from the theobromine group. Unlike with most catalysts, the selectivity did not depend on electronic or steric factors but rather on the position of the olefin relative to the theobromine group. (Figure presented.).
Intramolecular Parallel [4+3] Cycloadditions of Cyclopropane 1,1-Diesters with [3]Dendralenes: Efficient Construction of [5.3.0]Decane and Corresponding Polycyclic Skeletons
Zhang, Chi,Tian, Jun,Ren, Jun,Wang, Zhongwen
supporting information, p. 1231 - 1236 (2017/02/05)
Aiming to develop efficient and general strategies for construction of complex and diverse polycyclic skeletons, we have successfully developed [4+3]IMPC (intramolecular parallel cycloaddition) of cyclopropane 1,1-diesters with [3]dendralenes. With a combination of the [4+3]IMPC and subsequent [4+n] cycloadditions, trans-[5.3.0]decane skeleton and its corresponding structurally complex and diverse polycyclic variants could be constructed efficiently. This novel [4+3] cycloaddition reaction mode of donor–acceptor cyclopropanes proceeds as a result of the ring-strain relief of a trans-[3.3.0]octane. We strongly believe that the developed methods will demonstrate potential applications in natural products synthesis and drug discovery.
Oxo-rhenium-catalyzed deoxydehydration of polyols with hydroaromatic reductants
Boucher-Jacobs, Camille,Nicholas, Kenneth M.
supporting information, p. 1985 - 1990 (2015/06/08)
Several dihydroaromatic compounds are shown to be effective reducing agents in the oxo-metal-catalyzed deoxydehydration of diols and polyols to produce olefins and the corresponding arenes. NH4ReO4 and MeReO3 are active catalysts for the reactions. The most effective of the hydroaromatic reductants is indoline, which is oxidized to indole. Yields for a variety of diols and polyols range from 35% to 99%. Two hydrogen donors, 1,3-cyclohexadiene and dihydroanthracene, engage in tandem DODH/cycloaddition reactions. Competition experiments show that indoline is more reactive than representative alcohols in H-transfer. Indoline is shown to reduce MeReO3 to MeReO2 via an isolable adduct, MeReO3(indoline) (4), which has been structurally characterized and is suggested to be an intermediate in the catalytic DODH process.
Synthesis of spiroindanes by palladium-catalyzed oxidative annulation of non- or weakly activated 1,3-dienes involving C-H functionalization
Khan, Imtiaz,Chidipudi, Suresh Reddy,Lam, Hon Wai
supporting information, p. 2613 - 2616 (2015/03/05)
The synthesis of spiroindanes by the palladium-catalyzed oxidative annulation of non- or weakly activated 1,3-dienes with 2-aryl cyclic 1,3-dicarbonyl compounds is described. Examples of the dearomatizing oxidative annulation of 1,3-dienes with 1-aryl-2-naphthols are also presented. This journal is
Through-bond/through-space anion relay chemistry exploiting vinylepoxides as bifunctional linchpins
Chen, Ming Z.,Gutierrez, Osvaldo,Smith, Amos B.
supporting information, p. 1279 - 1282 (2014/03/21)
The development of new bifunctional linchpins that permit the union of diverse building blocks is essential for the synthetic utility of anion relay chemistry (ARC). The design, synthesis, and validation of three vinylepoxide linchpins for through-bond/through-space ARC are now reported. For negative charge migration, this class of bifunctional linchpins employs initial through-bond ARC by an SN2' reaction, followed by through-space ARC exploiting a 1,4-Brook rearrangement. The trans-disubstituted vinylepoxide linchpin yields a mixture of E/Z isomers, whereas the cis-disubstituted and the trans-trisubstituted vinylepoxide linchpins proceed to deliver three-component adducts with excellent E selectivity.
Simple and efficient 1,3-isomerization of allylic alcohols using a supported monomeric vanadium-oxide catalyst
Mitsudome, Takato,Sueoka, Shoichiro,Ikeda, Satoshi,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
, p. 2879 - 2882 (2013/10/21)
Promotion by group high five: Silica-supported monomeric vanadium-oxide promoted the isomerization of various allylic alcohols, including under scaled-up and solvent-free reaction conditions. This catalyst also exhibited high reusability with no drop in activity.
