Tetrabutylammonium bromide promoted efficient and chemoselective trimethylsilylation of primary and secondary alcohols under mild reaction conditions

2008 ◽  
Vol 5 (S1) ◽  
pp. S87-S90 ◽  
Author(s):  
F. Shirini ◽  
M. Abedini
2004 ◽  
Vol 82 (2) ◽  
pp. 206-214 ◽  
Author(s):  
Richard W Friesen ◽  
Laird A Trimble

4,7-Dichloroquinoline (1a) and 7-chloro-4-iodoquinoline (1b) undergo Suzuki cross-coupling reactions with arylboronic acids catalyzed by phosphine-free palladium acetate in boiling water. Using phenylboronic acid (2), the reaction of 1a provides 7-chloro-4-phenylquinoline (3) (78%) together with diphenylquinoline (4) (12%), while 1b reacts in a much more regioselective fashion and provides 3 in 98% isolated yield. Although 1b undergoes a more regioselective Suzuki reaction than 1a, additional important observations are that the overall reaction of 1b with 2 is three times slower than 1a and that the reaction occurs in the absence of tetrabutylammonium bromide. Using optimized reaction conditions, a variety of aryl and vinylboronic acids undergo regioselective Suzuki cross-coupling with 1b to provide the products 7, 10, and 11 in good to excellent yield.Key words: palladium, cross-coupling, regioselectivity, quinolines, boronic acids.


2021 ◽  
Vol 37 (3) ◽  
pp. 626-633
Author(s):  
Bhawana Arora ◽  
Jitendra Ojha ◽  
Pallavi Mishra

Oxidation of secondary alcohols is an important part of synthetic organic chemistry. Various studies are carried out at different reaction conditions to determine the best mechanistic pathways. In our study, oxidation of different secondary alcohols was done by using Benzimidazolium Fluorochromate in Dimethyl Sulphoxide, which is a non-aqueous solvent. Oxidation resulted in the formation of ketonic compounds. The reaction showed first order kinetics both in BIFC and in the alcohols. Hydrogen ions were used to catalyze the reaction. We selected four different temperatures to carry out our study. The correlation within the activation parameters like enthalpies and entropies was in accordance with the Exnerʼs criterion. The deuterated benzhydrol (PhCDOHPh) oxidation exhibited an important primary kinetic isotopic effect (kH / kD = 5.76) at 298 K. The solvent effect was studied using the multiparametric equations of Taft and Swain. There was no effect of addition of acrylonitrile on the oxidation rate. The mechanism involved sigmatropic rearrangement with the transfer of hydrogen ion taking place from alcohol to the oxidant via a cyclic chromate ester formation.


1990 ◽  
Vol 38 (9) ◽  
pp. 2377-2380 ◽  
Author(s):  
Hiroyuki AKITA ◽  
Harutami YAMADA ◽  
Hiroko MATSUKURA ◽  
Tadashi NAKATA ◽  
Takeshi OISHI

2014 ◽  
Vol 4 (8) ◽  
pp. 2526-2534 ◽  
Author(s):  
Laura M. Dornan ◽  
Gráinne M. A. Clendenning ◽  
Mateusz B. Pitak ◽  
Simon J. Coles ◽  
Mark J. Muldoon

The (HSA)Pd(OAc)2 complex (where HSA = 8-hydroxyquinoline-2-sulfonic acid) is a highly active catalyst for the oxidation of a range of secondary alcohols in 4–6 hours at a low loading of 0.5 mol%. The crystal structure has been obtained and the influence of reaction conditions on catalyst degradation was also examined.


Inorganics ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 97 ◽  
Author(s):  
Forberg ◽  
Kallmeier ◽  
Kempe

Novel synthetic routes to the commonly encountered indole motif are highly sought after. Tetrahydro-1H-indoles were synthesized for the first time from secondary alcohols and 2aminocyclohexanol in the presence of a well-established iridium catalyst using a modified synthetic procedure recently developed for the synthesis of hydrocarbazoles. The catalyst is stabilized by an inexpensive and easy-to-synthesize triazine based PN5P pincer ligand. The reaction proceeds through acceptorless dehydrogenative condensation (ADC) and yields the title compound, dihydrogen, and water and can thus be classified as sustainable synthesis. Overall, five examples, three of which were previously unknown compounds, were prepared. The propitious isolated yields and the mild reaction conditions show the synthetic value of this approach. These tetrahydroindoles can be quantitatively dehydrogenated over a heterogeneous Pd catalyst to yield the corresponding indoles.


2019 ◽  
Author(s):  
Laure Peilleron ◽  
Pascal Retailleau ◽  
Kevin Cariou

<div>In this study we describe the reactivity of unsaturated N-alkoxyureas in the presence of different combinations of a hypervalent iodine(III) reagent and a bromide source or TEMPO. Three complementary cyclizations can be achieved depending on the reaction conditions. On the one hand, PIFA with pyridinium bromide leads to an oxybromination reaction. On the other hand, bis(tert-butylcarbonyloxy)iodobenzene with tetrabutylammonium bromide or TEMPO triggers aminobromination or aminooxyamination reactions, respectively. Control experiments showed that while the first process is ionic, the other two follow a radical manifold.</div>


ChemInform ◽  
2010 ◽  
Vol 22 (18) ◽  
pp. no-no
Author(s):  
H. AKITA ◽  
H. YAMADA ◽  
H. MATSUKURA ◽  
T. NAKATA ◽  
T. OISHI

2018 ◽  
Vol 14 ◽  
pp. 2090-2097 ◽  
Author(s):  
Jiao-Na Han ◽  
Cong Du ◽  
Xinju Zhu ◽  
Zheng-Long Wang ◽  
Yue Zhu ◽  
...  

A cobalt-catalyzed C(sp2)–H alkoxylation of 1-naphthylamine derivatives has been disclosed, which represents an efficient approach to synthesize aryl ethers with broad functional group tolerance. It is noteworthy that secondary alcohols, such as hexafluoroisopropanol, isopropanol, isobutanol, and isopentanol, were well tolerated under the current catalytic system. Moreover, a series of biologically relevant fluorine-aryl ethers were easily obtained under mild reaction conditions after the removal of the directing group.


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