5658-46-8Relevant academic research and scientific papers
Contra-Thermodynamic Positional Isomerization of Olefins
Zhao, Kuo,Knowles, Robert R.
supporting information, p. 137 - 144 (2022/01/19)
A light-driven method for the contra-thermodynamic positional isomerization of olefins is described. In this work, stepwise PCET activation of a more substituted and more thermodynamically stable olefin substrate is mediated by an excited-state oxidant an
Electrochemical Vicinal Difluorination of Alkenes: Scalable and Amenable to Electron-Rich Substrates
Doobary, Sayad,Sedikides, Alexi T.,Caldora, Henry P.,Poole, Darren L.,Lennox, Alastair J. J.
supporting information, p. 1155 - 1160 (2019/12/11)
Fluorinated alkyl groups are important motifs in bioactive compounds, positively influencing pharmacokinetics, potency and conformation. The oxidative difluorination of alkenes represents an important strategy for their preparation, yet current methods are limited in their alkene-types and tolerance of electron-rich, readily oxidized functionalities, as well as in their safety and scalability. Herein, we report a method for the difluorination of a number of unactivated alkene-types that is tolerant of electron-rich functionality, giving products that are otherwise unattainable. Key to success is the electrochemical generation of a hypervalent iodine mediator using an “ex-cell” approach, which avoids oxidative substrate decomposition. The more sustainable conditions give good to excellent yields in up to decagram scales.
Synthesis of Piperidine Derivatives by Rhodium- Catalyzed Tandem Reaction of N-Sulfonyl-1,2,3-Triazole and Vinyl Ether
Yu, Sisi,An, Yuehui,Wang, Wenlin,Xu, Ze-Feng,Li, Chuan-Ying
supporting information, p. 2125 - 2130 (2018/04/17)
A chemoselective tandem reaction of 4-acyloxymethylene-1-sulfonyl-1,2,3-triazole and vinyl ether was reported, producing polysubstituted piperidine derivatives in up to 96% yield. The key intermediate N-sulfonyl 1-azadiene generated by migration of the OAc group to the α-imino rhodium carbene was isolated and a plausible mechanism was proposed. Several related ring systems were constructed from the highly functionalized products. (Figure presented.).
Hydroheteroarylation of Unactivated Alkenes Using N-Methoxyheteroarenium Salts
Ma, Xiaoshen,Dang, Hester,Rose, John A.,Rablen, Paul,Herzon, Seth B.
supporting information, p. 5998 - 6007 (2017/05/04)
We report the first reductive coupling of unactivated alkenes with N-methoxy pyridazinium, imidazolium, quinolinium, and isoquinolinium salts under hydrogen atom transfer (HAT) conditions, and an expanded scope for the coupling of alkenes with N-methoxy pyridinium salts. N-Methoxy pyridazinium, imidazolium, quinolinium, and isoquinolinium salts are accessible in 1-2 steps from the commercial arenes or arene N-oxides (25-99%). N-Methoxy imidazolium salts are accessible in three steps from commercial amines (50-85%). In total 36 discrete methoxyheteroarenium salts bearing electron-donating, electron-withdrawing, alkyl, aryl, halogen, and haloalkyl substituents were prepared (several in multigram quantities) and coupled with 38 different alkenes. The transformations proceed under neutral conditions at ambient temperature, provide monoalkylation products exclusively, and form a single alkene addition regioisomer. Preparatively useful and complementary site selectivities in the addition of secondary and tertiary radicals to pyidinium salts are documented: harder secondary radicals favor C-2 addition (2->10:1), while softer tertiary radicals favor bond formation to C-4 (4.7->29:1). A diene possessing a 1,2-disubstituted and 2,2-disubstituted alkene undergoes hydropyridylation at the latter exclusively (61%) suggesting useful site selectivities can be obtained in polyene substrates. The methoxypyridinium salts can also be employed in dehydrogenative arylation, borono-Minisci, and tandem arylation processes. Mechanistic studies support the involvement of a radical process.
Brook Rearrangement as Trigger for Carbene Generation: Synthesis of Stereodefined and Fully Substituted Cyclobutenes
Zhang, Fa-Guang,Marek, Ilan
supporting information, p. 8364 - 8370 (2017/06/28)
Through a sequence that can be performed in a single vessel, involving regio- and diastereoselective copper-catalyzed carbomagnesiation of cyclopropenes, reaction with acylsilanes, and addition of THF as cosolvent, Brook rearrangement can be triggered to furnish a wide range of cyclobutenes with exceptional diastereoselectivity. Accordingly, stereodefined and highly substituted cyclobutenes with contiguous quaternary carbon centers can be synthesized easily and in high yield. The new strategy constitutes an unprecedented application of Brook rearrangement, one which involves the intermediacy of carbene species.
HETEROARYL COMPOUNDS AS IRAK INHIBITORS AND USES THEREOF
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Paragraph 00191, (2017/05/02)
The present invention relates to compounds of Formula (I) and pharmaceutically acceptable compositions thereof, useful as IRAK inhibitors.
Decarboxylative alkenylation
Edwards, Jacob T.,Merchant, Rohan R.,McClymont, Kyle S.,Knouse, Kyle W.,Qin, Tian,Malins, Lara R.,Vokits, Benjamin,Shaw, Scott A.,Bao, Deng-Hui,Wei, Fu-Liang,Zhou, Ting,Eastgate, Martin D.,Baran, Phil S.
, p. 213 - 218 (2017/05/19)
Olefin chemistry, through pericyclic reactions, polymerizations, oxidations, or reductions, has an essential role in the manipulation of organic matter. Despite its importance, olefin synthesis still relies largely on chemistry introduced more than three decades ago, with metathesis being the most recent addition. Here we describe a simple method of accessing olefins with any substitution pattern or geometry from one of the most ubiquitous and variegated building blocks of chemistry: alkyl carboxylic acids. The activating principles used in amide-bond synthesis can therefore be used, with nickel- or iron-based catalysis, to extract carbon dioxide from a carboxylic acid and economically replace it with an organozinc-derived olefin on a molar scale. We prepare more than 60 olefins across a range of substrate classes, and the ability to simplify retrosynthetic analysis is exemplified with the preparation of 16 different natural products across 10 different families.
4 -SUBSTITUTED BENZOXABOROLE COMPOUNDS AND USES THEREOF
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Paragraph 00232, (2016/09/22)
Substituted benzoxaboroles whose structure comprises Formula (III), wherein R3 is selected from –CH3, –CH2CH3, –CH2=CH2, –CH2CH2CH3, –CH(CH3)sub
TRICYCLIC BENZOXABOROLE COMPOUNDS AND USES THEREOF
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Paragraph 00258-00259, (2015/02/25)
Compounds of Formula II wherein X is selected from chloro, fluoro, bromo and iodo, R1 and R2 are each independently selected from H, -CH3, -CH2CH3, -CH2CH2CH3, or -CH(CH3)2
Repairing the thiol-ene coupling reaction
Povie, Guillaume,Tran, Anh-Tuan,Bonnaffe, David,Habegger, Jacqueline,Hu, Zhaoyu,Le Narvor, Christine,Renaud, Philippe
supporting information, p. 3894 - 3898 (2014/05/06)
Thiol-ene coupling (TEC) reactions emerged as one of the most useful processes for coupling different molecular units under reaction mild conditions. However, TEC reactions involving weak C-H bonds (allylic and benzylic fragments) are difficult to run and often low yielding. Mechanistic studies demonstrate that hydrogen-atom transfer processes at allylic and benzylic positions are responsible for the lack of efficiency of the radical-chain process. These competing reactions cannot be prevented, but reported herein is a method to repair the chain process by running the reaction in the presence of triethylborane and catechol. Under these reaction conditions, a unique repair mechanism leads to an efficient chain reaction, which is demonstrated with a broad range of anomeric O-allyl sugar derivatives including mono-, di-, and tetrasaccharides bearing various functionalities and protecting groups. In good repair: Undesired hydrogen-atom transfers are responsible for the lack of efficiency in thiol-ene coupling reactions involving allyl glycosides. This competing reaction cannot be prevented but can be very efficiently repaired by carrying out the reaction in the presence of triethylborane and catechol.
