33235-14-2Relevant academic research and scientific papers
A General Approach to Deboronative Radical Chain Reactions with Pinacol Alkylboronic Esters
André-Joyaux, Emy,Kuzovlev, Andrey,Renaud, Philippe,Tappin, Nicholas D. C.
supporting information, p. 13859 - 13864 (2020/06/10)
The generation of carbon-centered radicals from air-sensitive organoboron compounds through nucleohomolytic substitution at boron is a general method to generate non-functionalized and functionalized radicals. Due to their reduced Lewis acidity, alkylboronic pinacol esters are not suitable substrates. We report their in situ conversion into alkylboronic catechol esters by boron-transesterification with a substoichiometric amount of catechol methyl borate combined with an array of radical chain processes. This simple one-pot radical-chain deboronative method enables the conversion of pinacol boronic esters into iodides, bromides, chlorides, and thioethers. The process is also suitable the formation of nitriles and allylated compounds through C?C bond formation using sulfonyl radical traps. The power of combining radical and classical boron chemistry is illustrated with a modular 5-membered ring formation using a combination of three-component coupling and protodeboronative cyclization.
Enantioselective Total Synthesis of (-)-Arcutinine
Nie, Wei,Gong, Jing,Chen, Zhihao,Liu, Jiazhen,Tian, Di,Song, Hao,Liu, Xiao-Yu,Qin, Yong
, p. 9712 - 9718 (2019/06/24)
The first total synthesis of an arcutine-type C20-diterpenoid alkaloid arcutinine has been achieved in both racemic and asymmetric forms. Construction of the C4 quaternary center and the pyrrolidine E ring in an early stage proved to be important for achieving the successful synthesis of the target alkaloid. Strategically, an asymmetric conjugate addition/aldol cascade and a decarboxylative allylation reaction allowed the establishment of the vicinal all-carbon quaternary stereocenters at C4 and C5. Furthermore, a sequence consisting of an intramolecular aza-Wacker cyclization, an oxidative dearomatization/intramolecular Diels-Alder cycloaddition cascade, and a ketyl-olefin cyclization enabled the assembly of the core structure and led to the total synthesis of arcutinine.
Deboronative cyanation of potassium alkyltrifluoroborates: Via photoredox catalysis
Dai, Jian-Jun,Zhang, Wen-Man,Shu, Yong-Jin,Sun, Yu-Yang,Xu, Jun,Feng, Yi-Si,Xu, Hua-Jian
, p. 6793 - 6796 (2016/06/01)
A photoredox catalytic method was developed for the direct cyanation of alkyltrifluoroborates. This reaction provides a new and useful transformation of the easily available alkyltrifluoroborates. The photocatalytic reaction can tolerate a variety of functional groups with mild reaction conditions. Mechanistic investigations are consistent with the present reaction following a radical pathway.
NICOTINAMIDE DERIVATIVES
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Page/Page column 224, (2010/01/12)
The present invention relates to compounds of the formula (I) and pharmaceutically acceptable salts and solvates thereof, wherein the substituents are defined herein, to compositions containing such compounds and to the uses of such compounds for the trea
Catalytic conjugate addition of cyanide to enones: Cooperative catalysis of Ni(0) and Gd(OTf)
Tanaka, Yuta,Kanai, Motomu,Shibasaki, Masakatsu
scheme or table, p. 2295 - 2298 (2009/05/27)
An efficient, synthetically useful catalytic cunjugate addition of cyanide to enones was developed using cooperative catalysis of Ni(0) and Gd(OTf) 3. The co-catalyst, Gd(OTf)3, dramatically accelerated the reaction. The substrate sc
A tandem Horner-Emmons olefination-gonjugate addition approach to the synthesis of 1,5-Disubstituted-6-azabicyclo[3.2.1]octanes based on the AE ring structure of the norditerpenoid alkaloid methyllycaconitine
Callis, David J.,Thomas, Noel F.,Pearson, David P. J.,Potter, Barry V. L.
, p. 4634 - 4640 (2007/10/03)
A novel Horner-Emmons olefination conjugate addition reaction of N-acetylamides to form 1,5-disubstituted-6-azabicyclo[3.2.1]octanes with two bridgehead quarternary carbon centers is reported. This reaction is a key step in an approach to the synthesis of small ring analogues based on the AE ring structure of the Delphinium norditerpenoid, methyllycaconitine (MLA) (1). Initially, 3-(hydroxymethyl)cyclohex-2-en-1-one (10) was selected as the starting material to these structures, but its generation proved inefficient. In contrast, the synthesis of 3-[(phenylthio)methyl]cyclohex-2-en-1-one (6) and 3-(1,3-dithian-2-yl)cyclohex-2-en-1-one (11) proceeded in good yield. Subsequent hydrocyanation, ketalization, reduction, acetylation, deprotection of the acetal, and Horner-Emmons olefination-conjugate addition reaction to form 1-[(phenylthio)methyl]-5-[(ethoxycarbonyl)methyl]-6-acetamido-6-azabicyclo[3.2. 1]octane(28), 1-(1,3-dithian-2-yl)-5-[(ethoxycarbonyl)methyl]-6-acetyl-6-azabicyclo[3.2.1] octane (29), respectively, are reported, as well as for readily available 3-methylcyclohex-2-en-1-one (12). Studies on the Pummerer rearrangement of 28 and subsequent desulfurization and reduction to form an hydroxymethyl-substituted azabicyclo[3.2.1.]octane (40) and then selective protection to form a protected hydroxyethyl N-ethyl (hydroxymethyl)azabicyclo-[3.2.1]octane (3) are also described.
Chemical Transformation of Terpenoids. VII. Syntheses of Chiral Segments, Key Building-Blocks for the Right Half of Taxane-Type Diterpenoids
Shibuya, Hirotaka,Tsujii, Shinji,Yamamoto, Yoshio,Miura, Hiromi,Kitagawa, Isao
, p. 3417 - 3427 (2007/10/02)
Two kinds of chiral segments, i.e. segment B-I (4) and segment B-II (5), which are potentially versatile building-blocks for construction of the right half of taxane-type diterpenoids, were synthesized from 3-methyl-2-cyclohexen-1-one (6) via optical reso
