13505-34-5Relevant academic research and scientific papers
Exceptionally Stable Ozonides. Influence of Methyl Substituents on the Course of Cyclopentene Ozonolyses and on the Reactivities of Ozonides
Mayr, Herbert,Baran, Janusz,Will, Elfriede,Yamakoshi, Hideyuki,Teshima, Koichi,Nojima, Masatomo
, p. 5055 - 5058 (1994)
Ozonolyses of 1,2,3,3,4,4,5,5-octamethyl- (1a), 1,2,3,3,4,4,5-heptamethyl- (1b), and 1,2,3,3,4,4-Hexamethyl cyclopentenes (1c) in methanol did not yield the ordinary hemiperacetals but gave the corresponding ozonides 6a-c instead.The ozonides 6a,b were extremely stable and remained intact even when refluxed with triphenylphosphine in tetrahydrofuran.Cycloreversion of the primary ozonides from unsymmetrically substituted 1,2,3,3-tetramethylcyclopentene (1d) and 1,5,5-trimethylcyclopentene (1f) was highly regioselective to yield intermediate ω-oxo carbonyl oxides with the geminal methyl groups remote from the carbonyl oxide groups.
Stereoselective synthesis of rac-(8R,13S,14S)-7-oxa-estra-4,9-diene-3,17-dione
Kang, Fu-An,Jain, Nareshkumar,Sui, Zhihua
, p. 9021 - 9024 (2006)
The first synthesis of a novel oxa-steroid, rac-(8R,13S,14S)-7-oxa-estra-4,9-diene-3,17-dione has been achieved via stereoselective catalytic hydrogenation of the tetra-substituted indene intermediate, whose structure was confirmed by X-ray crystallography. In contrast to the previous reports of similar indene systems, it was found that catalytic hydrogenation of indenes with a large substituent at the C-2 position and a bulky β-oriented protective group at the C-6 position resulted in cis-indanes instead of trans-indanes.
Synthesis of Diketones, Ketoesters, and Tetraketones by Electrochemical Oxidative Decarboxylation of Malonic Acid Derivatives: Application to the Synthesis of cis-Jasmone
Ma, Xiaofeng,Dewez, Damien F.,Du, Le,Luo, Xiya,Markó, István E.,Lam, Kevin
, (2018)
Disubstituted malonic acid derivatives are smoothly converted into diketones and ketoesters in good to excellent yield (68% to 91%) under electrochemical conditions. The scope can be extended to transform trisubstituted bis-malonic acids into tetraketones in 77% to 86% yield. The new method was applied to the total synthesis of cis-jasmone.
Dynamic Kinetic Sensitization of β-Dicarbonyl Compounds—Access to Medium-Sized Rings by De Mayo-Type Ring Expansion
Glorius, Frank,Guldi, Dirk M.,Henkel, Christian,James, Michael J.,Mai, Lukas A.,Paulisch, Tiffany O.,Strieth-Kalthoff, Felix
supporting information, (2021/12/27)
Herein, we present a photocatalyzed two-carbon ring expansion of β-dicarbonyl compounds with unactivated olefins that provides facile access to medium-sized rings. Selective sensitization of the substoichiometric enol tautomer enables reactivity of substr
METHODS AND COMPOSITIONS FOR MODULATING SPLICING
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Paragraph 0890-0891; 0934-0935, (2019/11/29)
Described herein are small molecule splicing modulator compounds that modulate splicing of mRNA, such as pre-mRNA, encoded by genes, and methods of use of the small molecule splicing modulator compounds for modulating splicing and treating diseases and conditions.
Synthesis of Diketones, Ketoesters, and Tetraketones by Electrochemical Oxidative Decarboxylation of Malonic Acid Derivatives: Application to the Synthesis of cis-Jasmone
Ma, Xiaofeng,Du, Le,Luo, Xiya,Markó, István E.,Dewez, Damien F.,Lam, Kevin
, p. 12044 - 12055 (2019/03/01)
Disubstituted malonic acid derivatives are smoothly converted into diketones and ketoesters in good to excellent yield (68% to 91%) under electrochemical conditions. The scope can be extended to transform trisubstituted bis-malonic acids into tetraketones in 77% to 86% yield. The new method was applied to the total synthesis of cis-jasmone.
Palladium-Catalyzed Long-Range Deconjugative Isomerization of Highly Substituted α,β-Unsaturated Carbonyl Compounds
Lin, Luqing,Romano, Ciro,Mazet, Clément
supporting information, p. 10344 - 10350 (2016/08/31)
The long-range deconjugative isomerization of a broad range of α,β-unsaturated amides, esters, and ketones by an in situ generated palladium hydride catalyst is described. This redox-economical process is triggered by a hydrometalation event and is thermodynamically driven by the refunctionalization of a primary or a secondary alcohol into an aldehyde or a ketone. Di-, tri-, and tetrasubstituted carbon-carbon double bonds react with similar efficiency; the system is tolerant toward a variety of functional groups, and olefin migration can be sustained over 30 carbon atoms. The refunctionalized products are usually isolated in good to excellent yield. Mechanistic investigations are in support of a chain-walking process consisting of repeated migratory insertions and β-H eliminations. The bidirectionality of the isomerization reaction was established by isotopic labeling experiments using a substrate with a double bond isolated from both terminal functions. The palladium hydride was also found to be directly involved in the product-forming tautomerization step. The ambiphilic character of the in situ generated [Pd-H] was demonstrated using isomeric trisubstituted α,β-unsaturated esters. Finally, the high levels of enantioselectivity obtained in the isomerization of a small set of α-substituted α,β-unsaturated ketones augur well for the successful development of an enantioselective version of this unconventional isomerization.
Ligand Effects in the Gold Catalyzed Hydration of Alkynes
Ebule, Rene E.,Malhotra, Deepika,Hammond, Gerald B.,Xu, Bo
supporting information, p. 1478 - 1481 (2016/05/19)
In the gold(I) (e. g. L-Au-OTf) catalyzed hydration of alkynes, the steric hindrance of ligands has a significant influence on the kinetics of the reaction, whereas their electronic effects are less influential. Very low loadings (ppm levels) of a gold catalyst containing a highly sterically hindered phosphine ligand (e. g. L4-Au-OTf) (L4=Me3(OMe)tBuXPhos) is able to catalyze the hydration of a wide range of alkyne substrates in good yields, at relatively low temperature.
Development of an azanoradamantane-type nitroxyl radical catalyst for class-selective oxidation of alcohols
Doi, Ryusuke,Shibuya, Masatoshi,Murayama, Tsukasa,Yamamoto, Yoshihiko,Iwabuchi, Yoshiharu
, p. 401 - 413 (2016/10/12)
The development of 1,5-dimethyl-9-azanoradamantane N-oxyl (DMN-AZADO; 1,5-dimethyl-Nor-AZADO, 2) as an efficient catalyst for the selective oxidation of primary alcohols in the presence of secondary alcohols is described. The compact and rigid structure of the azanoradamantane nucleus confers potent catalytic ability to DMN-AZADO (2). A variety of hindered primary alcohols such as neopentyl primary alcohols were efficiently oxidized by DMN-AZADO (2) to the corresponding aldehydes, whereas secondary alcohols remained intact. DMN-AZADO (2) also has high catalytic efficiency for one-pot oxidation from primary alcohols to the corresponding carboxylic acids in the presence of secondary alcohols and for oxidative lactonization from diols.
Hydration of alkynes at room temperature catalyzed by gold(I) isocyanide compounds
Xu, Yun,Hu, Xingbang,Shao, Jing,Yang, Guoqiang,Wu, Youting,Zhang, Zhibing
supporting information, p. 532 - 537 (2018/04/16)
An effective method using gold(I) isocyanide complexes as catalysts for the transformation of various alkynes to the corresponding ketones is successfully developed. The hydration process proceeds smoothly at room temperature with quite high yield (up to 99%). The catalytic center is the isocyanide-Au(I)+ cation. Further theoretical research reveals a direct hydration mechanism by H2O, and the rate-determining step has an energy barrier of 23.7 kcal mol?1. These results show a good example to reduce unnecessary steps and achieve milder reaction conditions at the same time for the hydration of alkynes.
