73448-13-2Relevant academic research and scientific papers
Strictly regio- and stereo-controlled α-alkenylation of bicyclic enone derivatives via palladium-catalyzed cross coupling and its application to a formal synthesis of (±)-carbacyclin
Negishi, Ei-ichi,Pour, Milan,Cederbaum, Frederik E.,Kotora, Martin
, p. 7057 - 7074 (1998)
A formal synthesis of carbacylin was achieved by preparing a known advanced intermediate 15 via Zr-promoted enyne bicyclization-carbonylation, Pd-catalyzed α-alkenylation of bicyclic enones, and conjugate reduction.
Towards the total synthesis of octalactin A
Bluet, Guillaume,Campagne, Jean-Marc
, p. 221 - 222 (2000)
In the course of a total synthesis of octalactin A, the (C1-C7) and (C8- C15) sub-units have been built up using catalytic asymmetric reactions; specifically, an asymmetric Shi epoxidation and a vinylogous Mukaiyama-aldol reaction.
Asymmetric reductive cyclization using the intramolecular conjugate addition of enolates onto α,β-unsaturated sulfoxides
Yoshizaki, Hiroki,Tanaka, Tadashi,Yoshii, Eiichi,Koizumi, Toru,Takeda, Kei
, p. 47 - 50 (1998)
Li(sec-Bu)3BH-mediated reductive cyclization of optically pure 8-(S)- p-tolylsulfinyl)-(2E,7Z)-octadienoate 9 and 7-(p-tolylsulfinyl)-2,6- heptadienoate 16 afforded trans-2-(p-tolylsulfinyl)-methyl)cyclohexane-1- carboxylate and trans-2(p-tolyl
Activation of 7-Endo over 6-Exo Epoxide Openings. Synthesis of Oxepane and Tetrahydropyran Systems
Nicolaou, K. C.,Prasad, C. V. C.,Somers, P. K.,Hwang, C.-K.
, p. 5335 - 5340 (1989)
Activation of 7-endo over 6-exo hydroxy epoxide opening by placement of an electron-rich double bond furthest away from the hydroxyl group leads to a reliable entry into trans- and cis-substituted oxepane systems.The scope and limitations of the method are discussed and extensions to bicyclic systems are presented.
Enantioselective Synthesis of Medium-Sized-Ring Lactones via Iridium-Catalyzed Z-Retentive Asymmetric Allylic Substitution Reaction
Ding, Lu,Song, Hao,Zheng, Chao,You, Shu-Li
supporting information, p. 4770 - 4775 (2022/03/27)
Medium-sized rings are important structural units, but their synthesis, especially in a highly enantioselective manner, has been a great challenge. Herein we report an enantioselective synthesis of medium-sized-ring lactones by an iridium-catalyzed Z-retentive asymmetric allylic substitution reaction. The reaction features mild conditions and a broad substrate scope. Various eight- to 11-membered-ring lactones can be afforded in moderate to excellent yields (up to 88%) and excellent enantioselectivity (up to 99% ee). The utilization of both Z-allyl precursors and an Ir catalyst is critical for the medium-sized-ring formation.
Diethylzinc-Mediated Radical 1,2-Addition of Alkenes and Alkynes
Li, Xin,He, Songtao,Song, Qiuling
supporting information, p. 2994 - 2999 (2021/05/04)
A novel diethylzinc-mediated radical 1,2-addition of perfluoroalkyl iodides to unactivated alkenes and alkynes is presented, which demonstrates a novel way to generate an ethyl difluoroacetate radical. This method is highly efficient and gives full conversions of the substrates, high yields of the products, and negligible byproducts and requires no column chromatography purifications. The mild conditions enable this protocol to exhibit excellent functional group compatibility.
Dictating Thermodynamic Control through Tethering: Applications to Stereoselective Bis-Spiroketal Synthesis
Asari, Austin H.,Floreancig, Paul E.
supporting information, p. 6622 - 6626 (2020/03/04)
Approaches to stereocontrol that invoke thermodynamic control fail when two or more potential products are energetically similar, but rational structural perturbations can be employed to break the energetic degeneracy and provide selective transformations. This manuscript illustrates that tethering is an effective approach for the stereoselective construction of bis-spiroketals with thermodynamically similar stereoisomers, providing a new approach to set remote stereocenters and prepare complex structures that have not previously been accessed stereoselectively.
Stereoselective Csp3?Csp2 Cross-Couplings of Chiral Secondary Alkylzinc Reagents with Alkenyl and Aryl Halides
Skotnitzki, Juri,Kremsmair, Alexander,Keefer, Daniel,Gong, Ye,de Vivie-Riedle, Regina,Knochel, Paul
supporting information, p. 320 - 324 (2019/11/26)
We report palladium-catalyzed cross-coupling reactions of chiral secondary non-stabilized dialkylzinc reagents, prepared from readily available chiral secondary alkyl iodides, with alkenyl and aryl halides. This method provides α-chiral alkenes and arenes with very high retention of configuration (dr up to 98:2) and satisfactory overall yields (up to 76 % for 3 reaction steps). The configurational stability of these chiral non-stabilized dialkylzinc reagents was determined and exceeded several hours at 25 °C. DFT calculations were performed to rationalize the stereoretention during the catalytic cycle. Furthermore, the cross-coupling reaction was applied in an efficient total synthesis of the sesquiterpenes (S)- and (R)-curcumene with control of the absolute stereochemistry.
Iodinated Choline Transport-Targeted Tracers
?vec, Pavel,Novy, Zbyněk,Ku?ka, Jan,Pet?ík, Milo?,Sedlá?ek, Ond?ej,Kucha?, Martin,Li?ková, Barbora,Medvedíková, Martina,Kolouchová, Kristyna,Groborz, Ond?ej,Loukotová, Lenka,Konefa?, Rafa? ?.,Hajdúch, Marián,Hruby, Martin
supporting information, p. 15960 - 15978 (2020/12/23)
We present a novel series of radioiodinated tracers and potential theranostics for diseases accompanied by pathological function of proteins involved in choline transport. Unlike choline analogues labeled with 11C or 18F that are currently used in the clinic, the iodinated compounds described herein are applicable in positron emission tomography, single-photon emission computed tomography, and potentially in therapy, depending on the iodine isotope selection. Moreover, favorable half-lives of iodine isotopes result in much less challenging synthesis by isotope exchange reaction. Six of the described compounds were nanomolar ligands, and the best compound possessed an affinity 100-fold greater than that of choline. Biodistribution data of 125I-labeled ligands in human prostate carcinoma bearing (PC-3) mice revealed two compounds with a biodistribution profile superior to that of [18F]fluorocholine.
Lewis Acid Catalyzed Electrophilic Aminomethyloxygenative Cyclization of Alkynols with N, O-Aminals
Chen, Anrong,Yu, Houjian,Yan, Jiaqi,Huang, Hanmin
supporting information, p. 755 - 759 (2020/01/28)
Lewis acid enables the electrophilic carbooxygenative cyclization of alkynols with N,O-aminals. The new process proceeds efficiently under very mild conditions via a pathway that is opposite to classical carbo-metalation. These reactions exhibit broad substrate generality and functional group compatibility, leading to a wide variety of 5-8-membered oxacycles bearing diverse functional groups. The cyclization products can be elaborated via simple functional group transformations to generate synthetically useful oxacycles.
