16339-75-6Relevant academic research and scientific papers
Total Synthesis of the Proposed Structure of Penasulfate A: L -Arabinose as a Source of Chirality
Gao, Yangguang,Cao, Zhou,Zhang, Qiang,Guo, Rui,Ding, Fei,You, Qingliang,Bi, Jingjing,Zhang, Yongmin
, p. 1908 - 1916 (2019)
The total synthesis of putative penasulfate A was effectively achieved by a convergent strategy with a longest linear sequence of 14 steps and overall yield of 8.6%. The highlights of our strategy involved an E-selective olefin cross-metathesis, Suzuki cross-coupling, and a copper(I)-catalyzed coupling reaction.
Total Synthesis and Structural Elucidation of Two Unusual Non-Methylene-Interrupted Fatty Acids in Ovaries of the Limpet Cellana toreuma
Shimada, Kazuaki,Sugawara, Ayako,Korenaga, Toshinobu,Kawashima, Hideki
, p. 1019 - 1032 (2017)
In our previous study, unusual odd-numbered dienoic acids with a terminal olefin were found as minor components in ovaries of the Japanese limpet Cellana toreuma, and the synthetic interests have been focused onto their structural confirmation and the inspection into their potential biological activity. Here, we describe an efficient and stereoselective total synthesis of two new unusual dienoic acids, 19:2?7,18 and 21:2?7,20, through a common pathway involving the strategic combination of alkyne-zipper reaction and Lindlar hydrogenation for the construction of their unique carbon chains. In our synthetic study, 2-propyn-1-ol was at first subjected to alkylation and alkyne-zipper reaction to form the two fragments, and the subsequent carbon chain elongation was achieved by the usual coupling reaction to obtain the C-19 and C-21 products bearing an internal acetylenic group. Then, the internal acetylenic group of these products was subjected to Lindlar hydrogenation to form a Z-alkenyl moiety, and the subsequent deprotection of the products was carried out under an acidic condition without isomerization of the internal Z-alkenyl group. Total synthesis of target fatty acids, 19:2?7,18 and 21:2?7,20, was finally accomplished by two-step oxidation of the resulting alcohols into carboxylic acids in a highly chemoselective manner, and the structures of these unusual natural fatty acids were finally elucidated by identifying the GC–MS spectra of the methyl esters of authentic and synthetic fatty acids.
A natural ɑ - glucosidase inhibitor Penasulfate A synthetic method (by machine translation)
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Paragraph 0029; 0046; 0047, (2019/02/04)
The invention provides a natural ɑ - glucosidase inhibitor Penasulfate A synthetic method, including by the 1, 12 - dodecanediol via 5 step synthesis 12 - thirteen carbon olefine acid, L - arabinose via the 3 step synthesis (2 S, 3 R) - 2, 3 - oxygen - isopropyl - 4 - pentene - 1, 2, 3 - triol, (S)- Roche ester via the 8 step synthesis of chiral methyl undecenyl fundamental frequency that mellow boron ester, 12 - thirteen alkenylene acid and (2 S, 3 R) - 2, 3 - oxygen - isopropyl - 4 - pentene - 1, 2, 3 - triol in GrubbsII catalyst under the action of the olefin metathesis reaction, and then with the (R)- piperidine - 2 - carboxylic acid methyl ester reaction to prepare amide, re-oxidation results in the aldehyde, Takai alkene alkylation by thirteen alkenylene iodide, with the insecticidal compositions of the fundamental frequency that chiral methyl mellow boron ester in Pd (PPh3 )4 Catalytic, ethyl alcohol thallium as alkali under the condition of the key Suzuki coupling, hydrogenation reduction, [...], sulfuric acid ester, shall Penasulfate A. The present invention provides natural product Penasulfate A throughout the synthetic route for the first time, the olefin metathesis reactions and Suzuki coupling as a key reaction, the line is comparatively simple high efficiency, a high degree of convergence, the operation is easy to grasp. (by machine translation)
Temporal separation of catalytic activities allows anti-Markovnikov reductive functionalization of terminal alkynes
Li, Le,Herzon, Seth B.
, p. 22 - 27 (2014/01/17)
There is currently great interest in the development of multistep catalytic processes in which one or several catalysts act sequentially to rapidly build complex molecular structures. Many enzymes - often the inspiration for new synthetic transformations - are capable of processing a single substrate through a chain of discrete, mechanistically distinct catalytic steps. Here, we describe an approach to emulate the efficiency of these natural reaction cascades within a synthetic catalyst by the temporal separation of catalytic activities. In this approach, a single catalyst exhibits multiple catalytic activities sequentially, allowing for the efficient processing of a substrate through a cascade pathway. Application of this design strategy has led to the development of a method to effect the anti-Markovnikov (linear-selective) reductive functionalization of terminal alkynes. The strategy of temporal separation may facilitate the development of other efficient synthetic reaction cascades.
A highly active and air-stable ruthenium complex for the ambient temperature anti-markovnikov reductive hydration of terminal alkynes
Zeng, Mingshuo,Li, Le,Herzon, Seth B.
supporting information, p. 7058 - 7067 (2014/06/09)
The conversion of terminal alkynes to functionalized products by the direct addition of heteroatom-based nucleophiles is an important aim in catalysis. We report the design, synthesis, and mechanistic studies of the half-sandwich ruthenium complex 12, which is a highly active catalyst for the anti-Markovnikov reductive hydration of alkynes. The key design element of 12 involves a tridentate nitrogen-based ligand that contains a hemilabile 3-(dimethylamino) propyl substituent. Under neutral conditions, the dimethylamino substituent coordinates to the ruthenium center to generate an air-stable, 18-electron, κ3-complex. Mechanistic studies show that the dimethylamino substituent is partially dissociated from the ruthenium center (by protonation) in the reaction media, thereby generating a vacant coordination site for catalysis. These studies also show that this substituent increases hydrogenation activity by promoting activation of the reductant. At least three catalytic cycles, involving the decarboxylation of formic acid, hydration of the alkyne, and hydrogenation of the intermediate aldehyde, operate concurrently in reactions mediated by 12. A wide array of terminal alkynes are efficiently processed to linear alcohols using as little as 2 mol % of 12 at ambient temperature, and the complex 12 is stable for at least two weeks under air. The studies outlined herein establish 12 as the most active and practical catalyst for anti-Markovnikov reductive hydration discovered to date, define the structural parameters of 12 underlying its activity and stability, and delineate design strategies for synthesis of other multifunctional catalysts.
Maltoside and Phosphocholine Derivatives, Uses thereof and Methods of Preparing Artificial Lipid Structures Thereof
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Paragraph 0053, (2013/04/24)
Disclosed are saccharide and phosphocholine derivatives. The derivatives include azide and alkyne derivatives which form one end of a variable length carbon chain. The opposite end of the variable length carbon chain is covalently linked to the saccharide or phosphocholine. The saccharide may be, for instance, a maltoside. The alkyne and azide derivatives of the saccharides and phosphocholine may be reacted together to form amphiphilic molecules useful in cellular membrane studies and applications. By adjusting the length of the carbon chain, the biochemical and biophysical properties of the resultant 1,4-disubstituted 1,2,3-triazole compounds may be custom tailored for the intended application. Resultant molecules may form micelles, bicelle, lipid bilayers and other like structures useful in the isolation and purification of membrane bound or membrane associated proteins and biochemical components. The saccharides and phosphocholine molecules may be alternatively substituted as desired to provide additional flexibility in designing the desired end product.
Regioselective reductive hydration of alkynes to form branched or linear alcohols
Li, Le,Herzon, Seth B.
supporting information, p. 17376 - 17379,4 (2020/09/16)
The regioselective reductive hydration of terminal alkynes using two complementary dual catalytic systems is described. Branched or linear alcohols are obtained in 75-96% yield with ?25:1 regioselectivity from the same starting materials. The method is compatible with terminal, di-, and trisubstituted alkenes. This reductive hydration constitutes a strategic surrogate to alkene oxyfunctionalization and may be of utility in multistep settings.
Design, chemical synthesis, and in vitro biological evaluation of simplified estradiol-adenosine hybrids as inhibitors of 17β-hydroxysteroid dehydrogenase type 1
Berube, Marie,Poirier, Donald
experimental part, p. 1180 - 1199 (2009/12/01)
A series of estradiol (E2) derivatives were designed to interact with, both the substrate- and the cofactor-binding sites of 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1). These analogues of potent E2-adenosine hybrid inhibitor EM-1745, where the adenosine moiety was replaced by a more stable benzene derivative, were synthesized from estrone using alkene cross-metathesis and Sonogashira coupling reactions as key steps. In vitro biological evaluation of these steroid derivatives revealed that a spacer of 13 methylenes, between the 16β-position of E2 and the adenosine mimic bearing a carboxylic acid, group, gave the best inhibition of 17β-HSD1.
The thread & cut method: Syntheses of molecular knot precursors
Fenlon, Edward E.,Ito, Brandon R.
supporting information; experimental part, p. 3065 - 3068 (2009/04/07)
A novel approach to molecular knots is described. This method may allow access to smaller and more complex knots. Two knot precursors, 1a and 1b, are efficiently prepared in overall yields of 9.6% and 8.7%, respectively. The convergent six-step syntheses utilize Frechet-type etherifications, alkyne/azide click cycloadditions, and bis-macrolactonizations. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Catalytic asymmetric synthesis of macrocyclic (E)-allylic alcohols from ω-alkynals via intramolecular 1-alkenylzinc/aldehyde additions
Oppolzer,Radinov,El-Sayed
, p. 4766 - 4770 (2007/10/03)
The ω-alkynals yielded macrocyclic (S)-allylic alcohols in a one-pot reaction sequence involving alkyne monohydroboration, boron to zinc transmetalation, and ((+)-DAIB)-catalyzed enantioselective intramolecular ring closure to the aldehyde function. A general study of this macrocyclization methodology is presented with respect to ligand type, size, and nature of the formed rings.
