2548-47-2Relevant articles and documents
Unexpected reactions of simple iron alkyls with a thiosulfinate ester capable of serving as a disulfur monoxide source
Powell, Kimberly R.,Elias, W. Jeff,Welker, Mark E.
, p. 81 - 89 (1991)
Attempts to use 4,5-diphenyl-3,6-dihydro-1,2-dithiin-1-oxide as a disulfur monoxide (S2O) source for S2O insertion into the metal carbon bond of CpMenFe(CO)2R (n = 0, 5; R = Me, Et) yielded unexpected iron thioester complexes, CpMenFe(CO)2SC(O)R.The characterization and independent syntheses of these thioester complexes are reported as well as the results of experiments designed to yield some information about the mechanism of formation of these thioester complexes.
Solid Acid-Catalyzed Dehydration of Pinacol Derivatives in Ionic Liquid: Simple and Efficient Access to Branched 1,3-Dienes
Hu, Yancheng,Li, Ning,Li, Guangyi,Wang, Aiqin,Cong, Yu,Wang, Xiaodong,Zhang, Tao
, p. 2576 - 2582 (2017)
The selective dehydration of pinacol derivatives to branched 1,3-dienes is extremely challenging because of the predominance of pinacol rearrangement. Herein, we successfully achieve this goal by employing a recyclable solid acid/ionic liquid catalyst system. The dehydration of alkyl- and cycloalkyl-derived diols in an Amberlyst-15/[Emim]Cl system afforded the corresponding 1,3-dienes in good yields, while a Nafion/[Emim]Cl system was demonstrated to be a better catalyst system for the dehydration of aryl-substituted substrates. Our protocol features straightforward and simple access to branched 1,3-dienes, high chemoselectivity, a recyclable catalyst system, a facile separation of dienes just by decantation, and a broad substrate scope.
Investigation of a transition metal-assisted retro Diels-Alder reaction used in the synthesis of transition metal S2O complexes
Urove, Greg A.,Welker, Mark E.,Eaton, Bruce E.
, p. 105 - 114 (1990)
Treatment of 4,5-diphenyl-3,6-dihydro-1,2-dithiin-1-oxide with coordinatively unsaturated transition metal complexes resulted in the production of S2O complexes and 2,3-diphenylbutadiene.A transition metal-assisted retro Diels-Alder mechanism has been proposed for this reaction.A series of IR and 1H NMR experiments and MNDO calculations on 4,5-diphenyl-3,6-dihydro-1,2-dithiin-1-oxide have been performed to gain additional information about this transformation.
Pseudomerohedrally twinned crystal structure of 2,3-diphenylbuta-1,3-diene
Lutz, Martin,Spek, Anthony L.,Van Der Wiel, Bas C.,Van Walree, Cornelis A.
, p. o300-o302 (2005)
The title compound, C16H14, is twinned by reticular pseudomerohedry of twin index 2. The primitive monoclinic cell of the single crystal can be transformed into a B-centred pseudoorthorhombic supercell with a fourfold volume. The two-fold twin operation about the reciprocal a* axis of the primitive monoclinic cell is co-directional with the approximate C 2 axis of the molecule and a symmetry element of the orthorhombic supercell. A tentative twin domain model is proposed.
Reductive Alkylation of Alkenyl Acetates with Alkyl Bromides by Nickel Catalysis
Bai, Yunfei,Han, Guan-Yu,He, Rong-De,Liu, Xue-Yuan,Pan, Xiaobo,Pang, Xiaobo,Shu, Xing-Zhong,Zhao, Zhen-Zhen
supporting information, (2021/12/14)
Catalytic alkylation of stable alkenyl C?O electrophiles is synthetically appealing, but studies to date have typically focused on the reactions with alkyl Grignard reagents. We report herein a cross-electrophile reaction of alkenyl acetates with alkyl bromides. This work has enabled a new method for the synthesis of aliphatic alkenes from alkenyl acetates to be established that can be used to add more structural complexity and molecular diversity with enhanced functionality tolerance. The method allows for a gram-scale reaction and modification of biologically active molecules, and it affords access to useful building blocks. Preliminary mechanistic studies reveal that the NiI species plays an essential role for the success of the coupling of these two reactivity-mismatched electrophiles.
Iron-Catalyzed Vinylzincation of Terminal Alkynes
Hu, Meng-Yang,Huang, Qiang,Su, Yu-Xuan,Sun, Wei,Wang, Wei-Na,Zhu, Shou-Fei
supporting information, (2022/01/08)
Organozinc reagents are among the most commonly used organometallic reagents in modern synthetic chemistry, and multifunctionalized organozinc reagents can be synthesized from structurally simple, readily available ones by means of alkyne carbozincation. However, this method suffers from poor tolerance for terminal alkynes, and transformation of the newly introduced organic groups is difficult, which limits its applications. Herein, we report a method for vinylzincation of terminal alkynes catalyzed by newly developed iron catalysts bearing 1,10-phenanthroline-imine ligands. This method provides efficient access to novel organozinc reagents with a diverse array of structures and functional groups from readily available vinylzinc reagents and terminal alkynes. The method features excellent functional group tolerance (tolerated functional groups include amino, amide, cyano, ester, hydroxyl, sulfonyl, acetal, phosphono, pyridyl), a good substrate scope (suitable terminal alkynes include aryl, alkenyl, and alkyl acetylenes bearing various functional groups), and high chemoselectivity, regioselectivity, and stereoselectivity. The method could significantly improve the synthetic efficiency of various important bioactive molecules, including vitamin A. Mechanistic studies indicate that the new iron-1,10-phenanthroline-imine catalysts developed in this study have an extremely crowded reaction pocket, which promotes efficient transfer of the vinyl group to the alkynes, disfavors substitution reactions between the zinc reagent and the terminal C–H bond of the alkynes, and prevents the further reactions of the products. Our findings show that iron catalysts can be superior to other metal catalysts in terms of activity, chemoselectivity, regioselectivity, and stereoselectivity when suitable ligands are used.
Copper-Catalyzed Dehydrogenative Diels-Alder Reaction
Jiang, Bing,Liang, Qiu-Ju,Han, Yu,Zhao, Meng,Xu, Yun-He,Loh, Teck-Peng
, p. 3215 - 3219 (2018/06/11)
A practical and effective copper-catalyzed dehydrogenative Diels-Alder reaction of gem-diesters and ketone with dienes has been established. The active dienophiles were generated in situ via a radical-based dehydrogenation process, which reacted with a wide variety of dienes to afford various polysubstituted cyclohexene derivatives in good to excellent yields.