105-29-3Relevant articles and documents
Intramolecular pyridone/enyne photocycloaddition: Partitioning of the [4 + 4] and [2 + 2] pathways
Kulyk, Svitlana,Dougherty, William G.,Kassel, W. Scott,Zdilla, Michael J.,Sieburth, Scott M.
, p. 2180 - 2183 (2011)
Chemical equations presented. Intramolecular photocycloaddition (>290 nm) between a 1,3-enyne and a 2-pyridone is far more selective than the intermolecular version; a three-atom linkage both controls regiochemistry and separates the [2 + 2] and [4 + 4] pathways. All four head-to-head, head-to-tail, tail-to-head, and tail-to-tail tetherings have been investigated. Linkage via the ene of the enyne leads to [2 + 2] products regardless of alkene geometry, whereas linkage through the yne results in [4 + 4] cycloadducts. The bridged 1,2,5-cyclooctatriene products of [4 + 4] cycloaddition are unstable and undergo a subsequent [2 + 2] dimerization reaction.
Total synthesis of paracentrone, C31-allenic opo-carotenoid
Murakami, Yusuke,Nakano, Masayuki,Shimofusa, Takuya,Furuichi, Noriyuki,Katsumura, Shigeo
, p. 1372 - 1374 (2005)
The stereocontrolled total synthesis of a C31-allenic apocarotenoid, paracentrone, was achieved by the convergent C20 + C11 = C31 strategy. The key elements of our synthesis were the Pd-catalyzed cross-coupling to stereoselectively construct the conjugated polyene backbone skeleton and the designed geometrical isomerization at the central double bond of the conjugated polyene chain. In addition, the terminal oxygenated cyclohexane ring having the allenic moiety was prepared by the highly diastereoselective Sharpless epoxidation under our own reaction conditions. The Royal Society of Chemistry 2005.
P(MeNCH2CH2)3N: An efficient catalyst for the desilylation of tert- butyldimethylsilyl ethers
Yu, Zhengkun,Verkade, John G.
, p. 2065 - 2068 (2000)
tert-Butyldimethylsilyl (TBDMS) ethers of primary, secondary, and tertiary alcohols and phenolic TBDMS ethers are desilylated to their corresponding alcohols and phenols, respectively, in DMSO, at 80 °C, in 68- 94% yield in the presence of 0.2-0.4 equiv of P(MeNCH2CH2)3N. Using P(i- PrNCH2CH2)3N as the catalyst, 85-97% yields of desilylated alcohols were obtained from TBDMS ethers of 1-octanol, 2-phenoxyethanol, and racemic α- phenyl ethanol. These are the first examples of desilylations of silyl ethers catalyzed by nonionic bases. Both catalysts were much less effective for the desilylation of tert-butyldiphenylsilyl (TBDPS) ethers (22-45% yield) under the same conditions as used for TBDMS ethers. Possible pathways involving nucleophilic attack of the anion of the solvent molecule (generated by the catalyst) at the Si-O bond of silyl ether or a prior activation of the silyl ether by the catalyst via a P-Si interaction followed by nucleophilic attack of the solvent anion are proposed on the basis of 1H and 31P NMR experimental data.
Synthesis of C6 acetylenic alcohols
Pu, Shuai,Zhang, A.I. Gui,Zhang, Shao Feng,Wang, Y.U. Liang
, p. 635 - 638 (2015)
C6 acetylenic alcohols are important intermediates in the synthesis of Vitamin A and carotenoids. New synthesis methods of the C6 acetylenic alcohols and their four derivatives are reported. These designed synthesis methods are useful improvement to the present methodologies. Structures of these compounds are confirmed by 1H NMR, IR and mass spectra analysis.
Chiral 1,2,3-Triazolium Salt Catalyzed Asymmetric Mono- and Dialkylation of 2,5-Diketopiperazines with the Construction of Tetrasubstituted Carbon Centers
Yang, Ju-Song,Lu, Ka,Li, Chen-Xiao,Zhao, Zu-Hang,Zhang, Xiao-Ming,Zhang, Fu-Min,Tu, Yong-Qiang
supporting information, (2022/01/22)
Novel asymmetric mono- and dialkylation reactions of α-substituted 2,5-diketopiperazines catalyzed by new chiral spirocyclic-amide-derived triazolium organocatalysts have been developed, resulting in a range of enantioenriched 2,5-diketopiperazine derivatives containing one or two tetrasubstituted carbon stereocenters. The reactions feature high yields (up to 98%), and excellent cis-diastereo- and enantioselectivities (up to >20:1 dr, >99 % ee), and they provide a new asymmetric synthetic approach to important functionalized 2,5-diketopiperazine skeletons. Furthermore, a possible reaction mechanism was proposed based on both control experiments and extensive DFT calculations.
Atom-Economical Cross-Coupling of Internal and Terminal Alkynes to Access 1,3-Enynes
Liu, Mingyu,Tang, Tianhua,Apolinar, Omar,Matsuura, Rei,Busacca, Carl A.,Qu, Bo,Fandrick, Daniel R.,Zatolochnaya, Olga V.,Senanayake, Chris H.,Song, Jinhua J.,Engle, Keary M.
supporting information, p. 3881 - 3888 (2021/04/06)
Selective carbon-carbon (C-C) bond formation in chemical synthesis generally requires prefunctionalized building blocks. However, the requisite prefunctionalization steps undermine the overall efficiency of synthetic sequences that rely on such reactions, which is particularly problematic in large-scale applications, such as in the commercial production of pharmaceuticals. Herein, we describe a selective and catalytic method for synthesizing 1,3-enynes without prefunctionalized building blocks. In this transformation several classes of unactivated internal acceptor alkynes can be coupled with terminal donor alkynes to deliver 1,3-enynes in a highly regio- and stereoselective manner. The scope of compatible acceptor alkynes includes propargyl alcohols, (homo)propargyl amine derivatives, and (homo)propargyl carboxamides. This method is facilitated by a tailored P,N-ligand that enables regioselective addition and suppresses secondary E/Z-isomerization of the product. The reaction is scalable and can operate effectively with as low as 0.5 mol % catalyst loading. The products are versatile intermediates that can participate in various downstream transformations. We also present preliminary mechanistic experiments that are consistent with a redox-neutral Pd(II) catalytic cycle.
Synthetic study of an intermediate towards paracentrone
Kaneyama, Taiki,Fujimaru, Kazumi,Takemura, Mami,Hasegawa, Kizuku,Hamada, Masahiro,Kishimoto, Takao,Urabe, Daisuke,Nakajima, Noriyuki
, p. 281 - 294 (2019/08/01)
Paracentrone (1), the second naturally occurring C31-methyl ketone apocarotenoid from fucoxanthin (2), was first isolated from the sea urchin Paracentrotus lividus. In this study, we focused on this carotenoid metabolite and report on a synthetic approach towards (3E)-(5R)-[(2R,4S)-2-hydroxy-4-(tert-butyldimethylsilyl)oxy-2,6,6-trimethylcyclohexylidene]-1-iodo-4-methyl-1,3, 5-hexatriene (5), a synthetic intermediate towards 1. This was obtained from epoxy acetylene (11) via (2E)-(4R)-[(2R,4S)-2-hydroxy-4-(tert-butyldimethyl-silyl)oxy-2,6,6-trimethylcyclohexylidene]-3-methylpenta-2,4-dien-1-ol (7).
Chemoenzymatic one-pot reaction of noncompatible catalysts: Combining enzymatic ester hydrolysis with Cu(i)/bipyridine catalyzed oxidation in aqueous medium
Sand, Henning,Weberskirch, Ralf
, p. 33614 - 33626 (2017/07/12)
The combination of chemical catalysts and biocatalysts in a one-pot reaction has attracted considerable interest in the past years. However, since each catalyst requires very different reaction conditions, chemoenzymatic one-pot reactions in aqueous media remain challenging and are limited today to metal-catalysts that display high activity in aqueous media. Here, we report the first combination of two incompatible catalytic systems, a lipase based ester hydrolysis with a water-sensitive Cu/bipyridine catalyzed oxidation reaction, in a one-pot reaction in aqueous medium (PBS buffer). Key to the solution was the compartmentalization of the Cu/bipyridine catalyst in a core-shell like nanoparticle. We show the synthesis and characterization of the Cu/bipyridine functionalized nanoparticles and the application in the oxidation of allylic and benzylic alcohols in aqueous media. Furthermore, the work demonstrates the implementation of a one-pot reaction process with optimized reaction conditions involving a lipase (CAL-B) to hydrolyze various acetate ester substrates in the first step, followed by oxidation of the resulting alcohols to the corresponding aldehydes under aerobic conditions in aqueous media.
Discovery of a Potent Free Fatty Acid 1 Receptor Agonist with Low Lipophilicity, Low Polar Surface Area, and Robust in Vivo Efficacy
Hansen, Steffen V. F.,Christiansen, Elisabeth,Urban, Christian,Hudson, Brian D.,Stocker, Claire J.,Due-Hansen, Maria E.,Wargent, Ed T.,Shimpukade, Bharat,Almeida, Reinaldo,Ejsing, Christer S.,Cawthorne, Michael A.,Kassack, Matthias U.,Milligan, Graeme,Ulven, Trond
supporting information, p. 2841 - 2846 (2016/04/10)
The free fatty acid receptor 1 (FFA1 or GPR40) is established as an interesting potential target for treatment of type 2 diabetes. However, to obtain optimal ligands, it may be necessary to limit both lipophilicity and polar surface area, translating to a need for small compounds. We here describe the identification of 24, a potent FFA1 agonist with low lipophilicity and very high ligand efficiency that exhibit robust glucose lowering effect.
A method of product yield allylol cis
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Paragraph 0030-0032, (2017/03/17)
The invention relates to a method for improving the yield of an allyl alcohol maleinoid form product, the formula (1) are isomerized into a mixture of the formula (2) and the formula (3), the formula (1), the formula (2) and the formula (3) are selected from alkyl, aryl and alkaryl, R2 is selected from H, alkyl and aryl, in a solvent and with the existence of a heterogeeous acid catalyst, the formula (1) is subjected to reaction, the solvent is water or a multiphase solvent system which comprises an aqueous phase and an organic solvent phase, and the organic solvent phase comprises an organic solvent which is selected from ethers, ketone or saturated fat hydrocarbon or a mixture of the same and is unmixed with water, the formula (1) is subjected to allylic rearrangement reaction, and a certain proportion of formula (3) is added into the allylic rearrangement reaction system of the formula (1); the gaseous phase interior label content of the formula (3) is greater than 95%. According to the invention, the forming of the product maleinoid form (2) is facilitated, the proportion of the maleinoid form (2) to the transform (3) is enhanced, and the yield of the maleinoid form (2) can be improved by about 13% compared with an original system.
