26232-97-3Relevant articles and documents
Transition-Metal-Free Valorization of Biomass-derived Levulinic Acid Derivatives: Synthesis of Curcumene and Xanthorrhizol
Fu, Yao,Gong, Tian-Jun,Xu, Wen-Yan,Zhuo, Kai-Feng
, p. 884 - 891 (2020/12/13)
Levulinic acid (LA) is acknowledged one of the most promising biomass-derived platform molecules and can be transformed into various value-added chemicals. Here, we report a new reaction process for the valorization of LA derivatives under transition-meta
Ligand-Controlled Regiodivergence in Nickel-Catalyzed Hydroarylation and Hydroalkenylation of Alkenyl Carboxylic Acids**
Deng, Ruohan,Engle, Keary M.,Fu, Yue,Gao, Yang,Li, Zi-Qi,Liu, Peng,Tran, Van T.
supporting information, p. 23306 - 23312 (2020/10/19)
A nickel-catalyzed regiodivergent hydroarylation and hydroalkenylation of unactivated alkenyl carboxylic acids is reported, whereby the ligand environment around the metal center dictates the regiochemical outcome. Markovnikov hydrofunctionalization products are obtained under mild ligand-free conditions, with up to 99 % yield and >20:1 selectivity. Alternatively, anti-Markovnikov products can be accessed with a novel 4,4-disubstituted Pyrox ligand in excellent yield and >20:1 selectivity. Both electronic and steric effects on the ligand contribute to the high yield and selectivity. Mechanistic studies suggest a change in the turnover-limiting and selectivity-determining step induced by the optimal ligand. DFT calculations reveal that in the anti-Markovnikov pathway, repulsion between the ligand and the alkyl group is minimized (by virtue of it being 1° versus 2°) in the rate- and regioselectivity-determining transmetalation transition state.
Heteroatom-directed Wacker oxidations. A protection-free synthesis of (-)-heliophenanthrone
Mukherjee, Parag,Sarkar, Tarun K.
supporting information; experimental part, p. 3060 - 3065 (2012/05/07)
The first enantioselective six-step synthesis of (-)-heliophenanthrone has been achieved without any protection-deprotection protocol at an overall yield of 28%. Key features of this synthesis comprise a heteroatom-directed Wacker oxidation of an internal cyclic olefin in addition to asymmetric Brown allylation and ring closing metathesis (RCM). The Royal Society of Chemistry 2012.
Erogorgiaene congeners and methods and intermediates useful in the preparation of same
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Page/Page column 28-29, (2010/04/30)
Disclosed are compounds having the formula: wherein R21 is an alkyl, aryl, alkoxy, hydroxy, or amino group or a halogen atom; wherein R2 is hydrogen or an alkyl, aryl, alkoxy, or amino group; wherein R23 and R24 are independently selected from hydrogen, an alkyl, aryl, alkoxy, hydroxy, or amino group, and a halogen atom or wherein R23 and R24, taken together with the carbon atom to which they are bound, form a ring; wherein R25 is hydrogen, an alkyl, aryl, alkoxy, hydroxy, or O-silyl group or a halogen atom; wherein Z, taken together with the carbons to which it is bonded, forms a 5-12 membered ring; and wherein Y is an electron withdrawing group. These compounds can be used to prepare erogorgiaene congeners, such as erogorgiaene, pseudopterosin A, helioporin E, pseudopteroxazole, colombiasin A, elisapoterosin B, elisabethadione, p-benzoquinone natural products, ileabethin, sinulobtain B, sinulobtain C, and sinulobtain D.
Direct synthesis of (+)-erogorgiaene through a kinetic enantiodifferentiating step
Davies, Huw M. L.,Walji, Abbas M.
, p. 1733 - 1735 (2007/10/03)
(Chemical Equation Presented) The combined approach of C-H activation and a Cope rearrangement catalyzed by a rhodium catalyst [Rh2(R-dosp) 4] (dosp = (N-dodecylbenzenesulfonyl)prolinate) is shown to be a very effective method for the construction of the three stereogenic centers (marked in red, see scheme) present in the diterpene erogorgiaene (1).
Chemoselective rhodium-carbenoid reaction with the aromatic nucleus: An efficient methodology for 2-indanones, 2- Tetralones and 2-benzosuberones and its application in the synthesis of (±)-ar-Himachalene
Sudrik,Nanjundiah,Sonawane
, p. 1103 - 1112 (2007/10/03)
Rhodium-carbenoid species derived from rhodium acetate- catalyzed decomposition of aryl alkyl α- diazoke-tones have been shown to display a chemoselective addition into the aromatic nucleus, instead of insertion into an aliphatic C-H site. The synthetic u
Efficient synthesis of (+/-)-ar-himachalene: Applications of chemoselective rhodium-carbenoid reaction with the aromatic nucleus
Sonawane, Harikisan R,Bellur, S Nanjundiah,Sudric, S G
, p. 606 - 607 (2007/10/02)
A practical synthesis of (+/-)-ar-Himachalene is realized utilizing selective rhodium-carbenoid insertion into the aromatic nucleus as a pivotal step.