- Identification of rapid access to polycyclic systems via a base-catalyzed cascade cyclization reaction and their biological evaluation
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A base-mediated cascade reaction between malonate esters and acrolein was developed to access complex polycyclic systems. This novel tandem reaction enables the simultaneous generation of up to seven new bonds and at least three new stereogenic centers. Mechanistic studies indicate a series of nucleophilic 1,4 and 1,6 Michael addition reactions occur, followed by an aldol condensation reaction, culminating in the formation of three fused rings. The compounds were characterized by NMR studies and the stereochemistry was confirmed by X-ray analysis. The ability to generate multigram quantities of such complex molecular scaffolds renders the method promising for medicinal chemistry campaigns. Herein, we also demonstrate that the lead compounds display promising anti-proliferative activities against human cancer cell models.
- Bollinger, John,Hadi, Victor,Ling, Taotao,Rivas, Fatima
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- Reactions of CH-acids with α,β-unsaturated aldehydes in ionic liquids
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Metal carbonate-catalyzed reactions of CH-acids (diethyl malonate, ethyl acetoacetate, ethyl cyanoacetate, and ethyl 2-acetyl- and 2-ethoxycarbonyl-5,9- dimethyldeca-4,8-dienoates) with α,β-unsaturated aldehydes (acrolein, crotonaldehyde, citral) were studied in an ionic liquid, 1-butyl-3- methylimidazolium hexafluorophosphate [bmim][PF6], and in a 1-butyl-3-methylimidazolium bromide ([bmim][Br]) - benzene system. The reactions with acrolein and crotonaldehyde afforded Michael addition products, those with citral resulted in Knoevenagel addition products. Sonication increased the yields of the Michael adducts. The ionic liquid [bmim][PF6] can be recovered and repeatedly used in the reactions.
- Kryshtal,Zhdankina,Astakhova,Zlotin
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- Synthesis of methaprogerol analogs
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Novel synthetic approaches towards analogs of methaprogerol, the efficient wound healing drug, were developed. Several hitherto unknown compounds obtained exhibited in vivo activity similar to methaprogerol. 2-(3-Dimethylaminopropyl)- 5-methylhex-4-enoic acid enhanced the efficacy of the treatment of diseases of various etiologies and different organ injuries by transplantation of mesenchymal stem cells (MSC) and MSC-derived cardiomyoblasts.
- Kryshtal,Zhdankina,Konoplyannikov,Tartakovsky,Serebryakov,Smirnov,Konoplyannikova,Agaeva,Zlotina
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- CATALYSIS OF THE MICHAEL REACTION
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Two nearly equivalent procedures have been evolved for catalysis of the Michael reaction: (i) potassium t-butoxide deposited on xonotlite; and (ii) aluminasupported potassium fluoride.These catalysts will undergo 150+ turnovers and enable Michael additions to be run at room temperature or below in good yields.
- Laszlo, Pierre,Pennetreau, Pascal
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- Enantioselective Synthesis of Substituted δ-Lactones by Cooperative Oxidative N-Heterocyclic Carbene and Lewis Acid Catalysis
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Efficient construction of complex cylcopentane- or cyclohexane-fused δ-lactones employing redox activation of enals using a chiral N-heterocyclic carbene and LiCl as cooperative catalysts is described. The organocascade proceeds with excellent diastereo- (>99:1) and enantioselectivity (up to >99% ee) and comprises the formation of three bonds with three contiguous stereocenters.
- Bera, Srikrishna,Daniliuc, Constantin G.,Studer, Armido
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supporting information
p. 4940 - 4943
(2015/11/03)
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- Rapid synthesis of substituted pyrrolines and pyrrolidines by nucleophilic ring closure at activated oximes
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Substituted pyrrolines are available by ring closure initiated by direct nucleophilic attack of stabilized enolates at the nitrogen of oximes activated with a leaving group, in a process which effectively out-competes the more usual Beckmann rearrangement. Subsequent reduction provides diastereoselective access to the corresponding pyrrolidines. This provides a rapid route to saturated heterocyclic systems from readily available precursors.
- Chandan, Nandkishor,Thompson, Amber L.,Moloney, Mark G.
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supporting information
p. 7863 - 7868
(2013/07/05)
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- 1,5-Hydrogen transfers from carbon to N-tributyltin substituted nitrogen
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1,5-H transfers from carbon to N-tributyltin substituted nitrogen proceeded smoothly and were much more efficient than 1,5-H transfers from carbon to ordinary nitrogen. 1,5-Tribuyltin group transfer from carbon to nitrogen and intramolecular addition of an aminyl radical to a nitrile group were also observed for the first time.
- Kim, Sunggak,Yeon, Kyu Man,Yoon, Kwang Sub
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p. 3919 - 3922
(2007/10/03)
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- NUCLEOPHILIC RING OPENING OF DIETHYL 1,1-CYCLOPROPANEDICARBOXYLATE USING Na2Fe(CO)4*3/2 DIOXANE
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Diethyl 1,1-cyclopropanedicarboxylate undergoes nucleophilic ring opening with Na2Fe(CO)4*3/2 dioxane under CO at room temperature to produce a variety of carbonylated products.
- Tamblyn, William H.,Waltermire, Robert E.
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p. 2803 - 2806
(2007/10/02)
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- Synthesis of 2-Alkyl-6-aza-8-oxabicyclooctanes
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Synthesis of 2-alkyl-6-aza-8-oxabicyclooctanes via an aminoalcohol acetal intermediate is described.
- Reddy, C. P.,Rao, R. Balaji
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p. 367 - 368
(2007/10/02)
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- Diesters of 6-cyano-2,2-tetrahydropyrandicarboxylates
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A compound of the formula STR1 wherein R' is lower alkyl, is useful as an intermediate in the preparation of a corresponding tricarboxylate, which is a useful detergent builder.
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