3238-98-0Relevant academic research and scientific papers
Iron(II) and Copper(I) Control the Total Regioselectivity in the Hydrobromination of Alkenes
Cruz, Daniel A.,Sinka, Victoria,De Armas, Pedro,Steingruber, Hugo Sebastian,Fernández, Israel,Martín, Víctor S.,Miranda, Pedro O.,Padrón, Juan I.
supporting information, p. 6105 - 6109 (2021/08/18)
A new method that allows the complete control of the regioselectivity of the hydrobromination reaction of alkenes is described. Herein, we report a radical procedure with TMSBr and oxygen as common reagents, where the formation of the anti-Markovnikov product occurs in the presence of parts per million amounts of the Cu(I) species and the formation of the Markovnikov product occurs in the presence of 30 mol % iron(II) bromide. Density functional theory calculations combined with Fukui's radical susceptibilities support the obtained results.
The Synthesis of Chiral Allyl Carbamates via Merger of Photoredox and Nickel Catalysis
Garbacz, Mateusz,Stecko, Sebastian
supporting information, p. 3213 - 3222 (2020/07/06)
A mild, and versatile, organophotoredox/Ni-mediated protocol was developed for the direct preparation of diverse, enantioenriched allyl carbamates. The reported approach represents a significant departure from classical step-by-step synthesis of allyl carbamates. This dual photoredox/Ni based strategy offers unrivalled capacity for convergent unification of readily available alkyl halides and chiral carbamates derived from 1-bromo-alken-3-ols with high chemoselectivity and efficiency. The reported photoredox/Ni catalyzed cross-coupling reaction is not limited to carbamates, but also to other O-derivatives such as esters, ethers, acetals, carbonates or silyl ethers. To demonstrate the utility of the reported protocol, the resulting allyl carbamates were transformed into functionalized non-racemic allylamines through a sigmatropic rearrangement reaction in enantiospecific manner. This approach allowed for synthesis of enantiomeric allylamines by a simple control of the geometry of a double bond of allyl carbamates. (Figure presented.).
Scandium(III) Triflate-Catalyzed anti-Markovnikov Hydrothiolation of Functionalized Olefins
Kuciski, Krzysztof,Pawluc, Piotr,Hreczycho, Grzegorz
, p. 3936 - 3942 (2016/01/25)
Scandium(III) triflate promoted highly selective addition of thiols to functionalized olefins under mild conditions. The addition follows anti-Markovnikov regioselectivities, which are unusual for Lewis acids-catalyzed hydrothiolation. This reaction marks broad functional groups tolerance, which opens a beneficial synthetic route to functionalized and biologically active thio-compounds. This method is broadly applicable and offers a simple work-up in the green manner.
Asymmetric synthesis of nonracemic primary amines via spiroborate-catalyzed reduction of pure (E)- and (Z)-O-benzyloximes: Applications toward the synthesis of calcimimetic agents
Ou, Wenhua,Espinosa, Sandraliz,Meléndez, Héctor J.,Farré, Silvia M.,Alvarez, Jaime L.,Torres, Valerie,Martínez, Ileanne,Santiago, Kiara M.,Ortiz-Marciales, Margarita
, p. 5314 - 5327 (2013/07/25)
Highly enantiopure (1-aryl)- and (1-naphthyl)-1-ethylamines were synthesized by the borane-mediated reduction of single-isomeric (E)- and (Z)-O-benzyloxime ethers using the stable spiroborate ester derived from (S)-diphenyl valinol and ethylene glycol as the chiral catalyst. Primary (R)-arylethylamines were prepared by the reduction of pure (Z)-ethanone oxime ethers in up to 99% ee using 15% of catalyst. Two convenient and facile approaches to the synthesis of new and known calcimimetic analogues employing enantiopure (1-naphthalen-1-yl)ethylamine as chiral precursor are described.
Synthesis and biological evaluation of berberine-thiophenyl hybrids as multi-functional agents: Inhibition of acetylcholinesterase, butyrylcholinesterase, and Aβ aggregation and antioxidant activity
Su, Tao,Xie, Shishun,Wei, Hui,Yan, Jun,Huang, Ling,Li, Xingshu
, p. 5830 - 5840 (2013/09/12)
A series of berberine-thiophenyl hybrids were designed, synthesised, and evaluated as inhibitors of acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and β-amyloid (Aβ) aggregation and as antioxidants. Among these hybrids, compounds 4f and 4i, berberine linked with o-methylthiophenyl and o-chlorothiophenyl by a 2-carbon spacer, were observed to be potent inhibitors of AChE, with IC50 values of 0.077 and 0.042 μM, respectively. Of the tested compounds, 4i was also the most potent inhibitor of BuChE, with an IC50 value of 0.662 μM. Kinetic studies and molecular modelling simulations of the AChE-inhibitor complex indicated that a mixed-competitive binding mode existed for these berberine derivatives. The biological studies also demonstrated that these hybrids displayed interesting activities, including Aβ aggregation inhibition and antioxidant properties.
OXAZOLE AND THIAZOLE DERIVATIVES AND THEIR USES 2
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Page/Page column 45, (2008/12/08)
Compounds of formula (I): wherein A, X, R1, R2, R3, R4, R5, R6 and R8 are as defined in the Specification are useful in the treatment of diseases where enhanced M3 receptor activ
Synthesis of the C1-C26 northern portion of azaspiracid-1: Kinetic versus thermodynamic control of the formation of the bis-spiroketal
Zhou, Xiao-Ti,Carter, Rich G.
, p. 1787 - 1790 (2007/10/03)
North-South divide: An efficient synthesis of the entire C1-C26 (northern) portion of azaspiracid-1 is disclosed (see picture). Key transformations include the formation of a bis-spiroketal, the oxidation of a sulfone at C10 to form a β,γ-unsaturated keto
Fluoro-sulfones
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, (2008/06/13)
Compounds of Formula I are described. They are antagonists of leukotrienes and SRS-A.
Fluoro-sulfones
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, (2008/06/13)
Compounds of Formula I STR1 the pharmaceutically acceptable salts, and the gamma-lactone form thereof are described. They are antagonists of leukotrienes and SRS-A.
A General Procedure for the Selective Oxidation of Sulfides to Sulfoxides by Nitric Acid: Tetrabromoaurate(III) Catalyst in a Biphasic System
Gasparrini, Francesco,Giovannoli, Mario,Misiti, Domenico,Natile, Giovanni,Palmieri, Gianni
, p. 1323 - 1328 (2007/10/02)
Tetrabromoaurate(III) is an efficient catalyst for the oxidation of sulfides to sulfoxides by nitric acid in a biphasic system (nitromethane/water).The system is selective and can be applied to the oxidation of any type of dialkyl and alkyl aryl sulfide and also of diaryl sulfides activated by electron-releasing substituents.The nature of the active species has been investigated in relation to the mechanistic aspects.
