773095-64-0Relevant academic research and scientific papers
Gold-Catalyzed Cyclization of 2-Alkynylaldehyde Cyclic Acetals via Hydride Shift for the Synthesis of Indenone Derivatives
Yamada, Tsuyoshi,Park, Kwihwan,Tachikawa, Takumu,Fujii, Akiko,Rudolph, Matthias,Hashmi, A. Stephen K.,Sajiki, Hironao
supporting information, p. 1883 - 1888 (2020/03/03)
An efficient gold-catalyzed cyclization of 2-alkynylaldehyde cyclic acetals has been developed for the synthesis of indenone derivatives. A wide variety of functionalized indenone derivatives can be obtained in good-to-excellent yields. HMBC and NOESY NMR analyses and mechanistic elucidation experiments revealed that the cyclization occurs via a 1,5-H shift. The cyclic acetal group promoted the 1,5-H shift by activating the benzylic C-H bond and preventing the migration of the alkoxy group by tethering both alkoxy groups.
Divergent C-H Insertion-Cyclization Cascades of N-Allyl Ynamides
Adcock, Holly V.,Chatzopoulou, Elli,Davies, Paul W.
, p. 15525 - 15529 (2016/01/26)
Gold carbene reactivity patterns were accessed by ynamide insertion into a C(sp3)-H bond. A substantial increase in molecular complexity occurred through the cascade polycyclization of N-allyl ynamides to form fused nitrogen-heterocycle scaffol
Intramolecular C-H activation through gold(I)-catalyzed reaction of iodoalkynes
Morn-Poladura, Pablo,Rubio, Eduardo,Gonzlez, Jos M.
supporting information, p. 3052 - 3055 (2015/04/14)
The cycloisomerization reaction of 1-(iodoethynyl)-2-(1-methoxyalkyl)arenes and related 2-alkyl-substituted derivatives gives the corresponding 3-iodo-1-substituted-1H-indene under the catalytic influence of IPrAuNTf2 [IPr = 1,3-bis(2,6-diisopropyl)phenylimidazol-2-ylidene; NTf2 = bis(trifluoromethanesulfonyl)imidate]. The reaction takes place in 1,2-dichloroethane at 80°C, and the addition of ttbp (2,4,6-tritert-butylpyrimidine) is beneficial to accomplish this new transformation in high yield. The overall reaction implies initial assembly of an intermediate gold vinylidene upon alkyne activation by gold(I) and a 1,2-iodine-shift. Deuterium labeling and crossover experiments, the magnitude of the recorded kinetic primary isotopic effect, and the results obtained from the reaction of selected stereochemical probes strongly provide support for concerted insertion of the benzylic C-H bond into gold vinylidene as the step responsible for the formation of the new carbon-carbon bond.
Cu-catalyzed 1,2-dihydroisoquinolines synthesis from o-ethynyl benzacetals and sulfonyl azides
Sun, Lang,Zhu, Yuanxun,Lu, Ping,Wang, Yanguang
supporting information, p. 5894 - 5897 (2013/12/04)
An efficient synthesis of 1,3-/1,1-dialkoxy 1,2-dihydroisoquinolines from o-ethynylbenzacetals and sulfonyl azides via a cascade process combining copper-catalyzed alkyne-azide cycloaddition (CuAAC), Dimroth rearrangement, 1,5-OR shift/1,5-H shift, and 6π-electrocyclic ring closure (6π-ERC) is described. Extension of the produced 1,3-dialkoxy-1,2-dihydroisoquinolines to isoquinolium salts is also disclosed.
Thermal cyclization of phenylallenes that contain ortho-1,3-dioxolan-2-yl groups: New cascade reactions initiated by 1,5-hydride shifts of acetalic hatoms
Alajarin, Mateo,Bonillo, Baltasar,Marin-Luna, Marta,Sanchez-Andrada, Pilar,Vidal, Angel
supporting information, p. 16093 - 16103 (2014/04/03)
A series of 2-(1,3-dioxolan-2-yl)phenylallenes that contained a range of substituents (alkyl, aryl, phosphinyl, alkoxycarbonyl, sulfonyl) at the cumulenic C3 position were prepared by using a diverse range of synthetic strategies and converted into their respective 1-(2-hydroxy)-ethoxy-2- substituted naphthalenes by smooth thermal activation in toluene solution. Electron-withdrawing groups at the C3 position accelerated these tandem processes, which consisted of 1)an initial hydride-like [1,5]-H shift of the acetalic Hatom onto the central cumulene carbon atom; 2)a subsequent 6π-electrocyclic ring-closure of the resulting reactive ortho-xylylenes; and 3)a final aromatization step with concomitant ring-opening of the 1,3-dioxolane fragment. If the 1,3-dioxolane ring of the starting allenes was replaced by a dimethoxymethyl group, the reactions led to mixtures of two disubstituted naphthalenes, which were formed by the migration of either the acetalic Hatom or the methoxy group, with the latter migration occurring to a lesser extent. Two of the final 1,2-disubstituted naphthalenes were converted into their corresponding naphtho-fused dioxaphosphepine or dioxepinone through an intramolecular transesterification reaction. A DFT computational study accounted for the beneficial influence of the 1,3-dioxolane fragment on the carbon atom from which the H-shift took place and also of the electron-withdrawing substituents on the allene terminus. Remarkably, in the processes that contained a sulfonyl substituent, the conrotatory 6π-electrocyclization step was of lower activation energy than the alternative disrotatory mode.
Synthesis of the 3-methylene-2-vinyltetrahydropyran unit; the hallmark of the sesquiterpene, hodgsonox
Barlow, Anna J.,Compton, Benjamin J.,Weavers, Rex T.
, p. 2470 - 2475 (2007/10/03)
(Chemical Equation Presented) The synthesis of some simple compounds containing the previously unreported 3-methylene-2-vinyltetrahydropyran system, a unique feature of the liverwort metabolite, hodgsonoxis reported. Key features are the creation of an ac
