63165-30-0Relevant academic research and scientific papers
Stereoselective Total Synthesis of (-)-(2 S,4 R)-3′-Methoxyl Citreochlorol: Preparation and Use of New Proline-Based Auxiliary for Asymmetric Acetate Aldol Reaction
Sunnapu, Ranganayakulu,Banoth, Saikumar Naik,Reyno,Thomas, Aleena,Venugopal, Navyasree,Rajendar, Goreti
, p. 4103 - 4113 (2020/03/05)
The first stereoselective total synthesis of (-)-(2S,4R)-3′-methoxy citreochlorol and (-)-(2S,4S)-3′-methoxy citreochlorol is demonstrated. A proline-based imidazolidinone was synthesized and used as chiral auxiliary for asymmetric acetate aldol reaction to generate initial chirality in the targeted molecule. Geminal dichloromethane functionality was introduced by the addition of in situ generated dichloromethyllithium to Weinreb's amide functional group.
Copper-Catalyzed Cascade Cyclization of Indolyl Homopropargyl Amides: Stereospecific Construction of Bridged Aza-[n.2.1] Skeletons
Tan, Tong-De,Zhu, Xin-Qi,Bu, Hao-Zhen,Deng, Guocheng,Chen, Yang-Bo,Liu, Rai-Shung,Ye, Long-Wu
supporting information, p. 9632 - 9639 (2019/06/27)
Catalytic cycloisomerization-initiated cascade cyclizations of terminal alkynes have received tremendous interest, and been widely used in the facile synthesis of a diverse array of valuable complex heterocycles. However, these tandem reactions have been mostly limited to noble-metal catalysis, and are initiated by an exo-cyclization pathway. Reported herein is an unprecedented copper-catalyzed endo-cyclization-initiated tandem reaction of indolyl homopropargyl amides, where copper catalyzes both the hydroamination and Friedel–Crafts alkylation process. This method allows the practical and atom-economical synthesis of valuable bridged aza-[n.2.1] skeletons (n=3–6) with wide substrate scope, and excellent diastereoselectivity and enantioselectivity by a chirality-transfer strategy. Moreover, the mechanistic rationale for this novel cascade cyclization is also strongly supported by control experiments, and is distinctively different from the related gold catalysis.
A straightforward organocatalytic alkylation of 2-arylacetaldehydes: An approach towards bisabolanes
Gualandi, Andrea,Canestrari, Pietro,Emer, Enrico,Cozzi, Pier Giorgio
supporting information, p. 528 - 536 (2014/05/20)
A highly stereoselective organocatalytic aalkylation of 2-arylacetaldehydes with a commercially available carbenium tetrafluoroborate is described. The stereoselective alkylation was carried out in acetonitrile/ water, under air in the presence of a commercially available imidazolidinone (MacMillan's catalyst). Key intermediates for the synthesis of bisabolanes were obtained through a simple chemistry. In particular a direct, enantioselective and facile synthesis of (R)-(-)-curcumene is described.
Selective formation of six-membered oxa- and carbocycles by the In(III)-activated ring closure of acetylenic substrates
Qiu, Wen-Wei,Surendra, Karavadhi,Yin, Liang,Corey
supporting information; experimental part, p. 5893 - 5895 (2011/12/16)
Fifteen examples are disclosed of efficient In(III)-catalyzed six-membered ring closure leading to bi-, tri-, and tetracyclic products.
Radical-mediated cyclisation of ω-aryl-β-dicarbonyl compounds to tetrahydrobenzocyclohepten-6-ones, hexahydrobenzocycloocten-6-ones and naphthalen-2(1H)-ones
Jamie, Joanne F.,Rickards, Rodney W.
, p. 3613 - 3621 (2007/10/03)
Manganese(III) acetate in acetic acid promotes efficient radical-mediated oxidative cyclisation of ε-aryl-β-dicarbonyl and Z-γ,δ-unsaturated δ-aryl-β-dicarbonyl compounds carrying electron-releasing groups in the aromatic ring, forming 6,7,8,9-tetrahydro-5H-benzocyclohepten-6-ones and naphthalen-2(1H)-ones, respectively. The process is accompanied by secondary acetoxylation at the activated benzylic position of the initial cyclisation products, and is exemplified by the conversions of the ε- and δ-aryl-β-dicarbonyl compounds 6 and 11 into the benzocycloheptenone 18 and the naphthalenone 21, respectively. Application of the oxidation to the formation of 8-membered hexahydro- and tetrahydro-benzocycloocten-6-ones 19 and 22 from ζ-aryl-β-dicarbonyl and Z-γ,δ-unsaturated ζ-aryl-β-dicarbonyl compounds is limited by low reactivity, and in the latter case, by radical rearrangement followed by cyclisation to a tetralin.
A Rapid, Convergent, and Regioselective Synthesis of Anthracenes
Fitzgerald, John J.,Drysdale, Neville E.,Olofson, R. A.
, p. 7122 - 7126 (2007/10/02)
Anthracenes are obtained in moderate to good yield by the simultaneous treatment of benzocyclobutenols and halobenzenes with LTMP in tetrahydropyran.In the key step of this one-pot process, o-toluoyl anion intermediates from the known ring-opening of benzocyclobutenoxides add to halobenzene derived arynes.Methoxy-substituted benzocyclobutenols which are readily made regiospecifically by known methods also react regiospecifically with the single benzyne generated from either a 2- or 3-haloanisole.For example, the only trimethoxyanthracene isolated (48percent yield) from the reaction of 6-methoxybenzocyclobutenol (8) with 5-chloro-1,3-dimethoxybenzene is the 1,3,8-isomer 20.When 1,2-dihydrocyclobutaphenanthren-1-ol (14) and/or halonaphthalenes are the reactants, benzannulated anthracenes are formed; e.g., tribenzanthracene in 68percent yield from 14 and bromonaphthalene.In another extension, pentaphene (31) was made in one pot from o-dichlorobenzene.
