Direct Nucleophilic Substitution of Alcohols by Brønsted or Lewis Acids Activation: An Update

2021 ◽  
pp. 123-154
Author(s):  
Pier Giorgio Cozzi ◽  
Andrea Gualandi ◽  
Luca Mengozzi ◽  
Elisabetta Manoni ◽  
Claire Margaret Wilson
Keyword(s):  
Nucleophilic Substitution ◽  
Lewis Acids

scholarly journals The Reaction of Hydrogen Halides with Tetrahydroborate Anion and Hexahydro-Closo-Hexaborate Dianion

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3754
Author(s):  
Igor E. Golub ◽  
Oleg A. Filippov ◽  
Natalia V. Belkova ◽  
Lina M. Epstein ◽  
Elena S. Shubina
Keyword(s):  
Dft Calculations ◽  
Nucleophilic Substitution ◽  
Solvent Effects ◽  
Lewis Acids ◽  
Hydrogen Halides ◽  
Hydride Ion ◽  
Low Degree ◽  
Successive Substitution ◽  
Electron Deficiency ◽  
Ab Initio Dft

The mechanism of the consecutive halogenation of the tetrahydroborate anion [BH4]− by hydrogen halides (HX, X = F, Cl, Br) and hexahydro-closo-hexaborate dianion [B6H6]2− by HCl via electrophile-induced nucleophilic substitution (EINS) was established by ab initio DFT calculations [M06/6-311++G(d,p) and wB97XD/6-311++G(d,p)] in acetonitrile (MeCN), taking into account non-specific solvent effects (SMD model). Successive substitution of H− by X− resulted in increased electron deficiency of borohydrides and changes in the character of boron atoms from nucleophilic to highly electrophilic. This, in turn, increased the tendency of the B–H bond to transfer a proton rather than a hydride ion. Thus, the regularities established suggested that it should be possible to carry out halogenation more selectively with the targeted synthesis of halogen derivatives with a low degree of substitution, by stabilization of H2 complex, or by carrying out a nucleophilic substitution of B–H bonds activated by interaction with Lewis acids (BL3).

Cationic palladium(ii)-catalyzed dehydrative nucleophilic substitutions of benzhydryl alcohols with electron-deficient benzenethiols in water

2016 ◽  
Vol 14 (29) ◽  
pp. 7038-7045 ◽  
Author(s):  
Hidemasa Hikawa ◽  
Yumo Machino ◽  
Mariko Toyomoto ◽  
Shoko Kikkawa ◽  
Isao Azumaya
Keyword(s):  
Nucleophilic Substitution ◽  
Lewis Acids ◽  
Nucleophilic Substitutions ◽  
Cationic Palladium

An efficient direct nucleophilic substitution of benzhydryl alcohols with electron-deficient benzenethiols using cationic Pd(ii) catalysts as Lewis acids in water is reported.

The Synthesis of New Selenium-containing Heterocycles by the Oxidation Reaction of 2,4-Diaryltetrahydro-4H-selenochromenes

2020 ◽  
Vol 24 (15) ◽  
pp. 1663-1668
Author(s):  
Dmitriy Yurievich Direnko ◽  
Boris Ivanovich Drevko ◽  
Yaroslav Borisovich Drevko
Keyword(s):  
Nucleophilic Substitution ◽  
Chlorine Atom ◽  
Oxidation Reaction ◽  
Heterocyclic Fragment ◽  
Oxidative Aromatization

We have explored the reactions of tetrahydro-4H-selenochromenes in the presence of phosphoric pentachloride, and synthesized new condensate aroylbenzoselenophenes. During the reactions, tetrahydro-4H-selenochromenes with phosphoric pentachloride underwent oxidative aromatization and nucleophilic substitution for a chlorine atom of one of the protons in the alicyclic fragment. Also, the narrowing of the heterocyclic fragment occurred as in synthesized selenium-containing compounds earlier transformed into the corresponding condensate aroylbenzoselenophenes.

On the Reaction of 2,5-Dihydroxy-[1,4]-benzoquinone with Diamines – Strain-induced Reactivity Effects

2020 ◽  
Vol 24 ◽  
Author(s):  
Hubert Hettegger ◽  
Andreas Hofinger ◽  
Thomas Rosenau
Keyword(s):  
Nucleophilic Substitution ◽  
Product Structure ◽  
Carbonyl Groups ◽  
Reaction Products ◽  
Double Bonds ◽  
Oh Groups ◽  
Natural Geometry ◽  
Quinoid Structure ◽  
Bond Localization

: The regioselectivity of the reaction of 2,5-dihydroxy-[1,4]-benzoquinone (DHBQ) with diamines could not be explained satisfactorily so far. In general, the reaction products can be derived from the tautomeric ortho-quinoid structure of a hypothetical 4,5-dihydroxy-[1,2]-benzoquinone. However, both aromatic and aliphatic 1,2-diamines form in some cases phenazines, formally by diimine formation on the quinoid carbonyl groups, and in other cases the corresponding 1,2- diamino-[1,2]-benzoquinones, by nucleophilic substitution of the OH groups, the regioselectivity apparently not following any discernible pattern. The reactivity was now explained by an adapted theory of strain-induced bond localization (SIBL). Here, the preservation of the "natural" geometry of the two quinoid C–C double bonds (C3=C4 and C5=C6) as well as the N–N distance of the co-reacting diamine are crucial. A decrease of the annulation angle sum (N–C4–C5 + C4–C5–N) is tolerated well and the 4,5-diamino-ortho-quinones, having relatively short N–N spacings are formed. An increase in the angular sum is energetically unfavorable, so that diamines with a larger N–N distance afford the corresponding ortho-quinone imines. Thus, for the reaction of DHBQ with diamines, exact predictions of the regioselectivity, and the resulting product structure, can be made on the basis of simple computations of bond spacings and product geometries.

Synthesis of Diastereomeric Pyrrolidine Sulfamides via Anchimerically Assisted Nucleophilic Substitution Reactions

2018 ◽  
Vol 15 (5) ◽  
pp. 352-358
Author(s):  
Jorge Vargas-Caporali ◽  
Arie van der Lee ◽  
Georges Dewynter ◽  
Eusebio Juaristi
Keyword(s):  
Nucleophilic Substitution ◽  
Substitution Reactions ◽  
Nucleophilic Substitution Reactions

The preparation of 3-amino-3-deoxy-1,2-O-isopropylidene-α-L-erythrofuranose, 3-amino-3-deoxy-1,2-O-isopropylidene-β-D-threofuranose and their derivatives

1980 ◽  
Vol 45 (12) ◽  
pp. 3378-3390 ◽  
Author(s):  
Jiří Jarý ◽  
Milena Masojídková ◽  
Ivan Kozák ◽  
Miroslav Marek ◽  
Jan Staněk
Keyword(s):  
Nucleophilic Substitution ◽  
Sodium Azide ◽  
Sodium Benzoate ◽  
Nmr Spectra ◽  
Subsequent Reduction ◽  
H Nmr ◽  
Amino Derivatives

The title amino derivatives VI and XIV were prepared by nucleophilic substitution of p-toluenesulfonyl derivatives II and XVII with sodium azide or hydrazine and subsequent reduction. Nucleophilic substitution of compounds II and XVII with sodium benzoate was also investigated. The 1H NMR spectra of the substances prepared are discussed.

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