scholarly journals Highly Efficient and Facile Method for Synthesis of 2-Substituted Benzimidazoles via Reductive Cyclization of O-Nitroaniline and Aryl Aldehydes

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Hossein Naeimi ◽  
Nasrin Alishahi
Keyword(s):  
Room Temperature ◽  
Reaction Times ◽  
Starting Material ◽  
Reductive Cyclization ◽  
Aryl Aldehydes ◽  
Mild Conditions ◽  
Highly Efficient ◽  
Convenient Synthesis

A versatile and convenient synthesis of 2-substituted benzimidazoles, using o-nitroaniline as starting material with several aryl aldehydes, has been accomplished by using a small amount of a reluctant agent. The reaction was carried out under very mild conditions at room temperature. The yields obtained are very good in reasonably short reaction times.

A Highly Efficient Method for the Bromination of Alkenes, Alkynes and Ketones Using Dimethyl Sulfoxide and Oxalyl Bromide

Synthesis ◽  
2018 ◽  
Vol 50 (21) ◽  
pp. 4325-4335 ◽  
Author(s):  
Hongyu Tian ◽  
Baoguo Sun ◽  
Rui Ding ◽  
Jiaqi Li ◽  
Wenyi Jiao ◽  
...  
Keyword(s):  
Dimethyl Sulfoxide ◽  
Efficient Method ◽  
Low Cost ◽  
Reaction Times ◽  
Attractive Alternative ◽  
Mild Conditions ◽  
Highly Efficient

The pairing of DMSO and oxalyl bromide is reported as a highly efficient brominating reagent for various alkenes, alkynes and ketones. This bromination approach demonstrates remarkable advantages, such as mild conditions, low cost, short reaction times, provides excellent yields in most cases and represents a very attractive alternative for the preparation of dibromides and α-bromoketones.

scholarly journals REGIOSELECTIVE AND FACILE OXIDATIVE THIOCYANATION OF ANILINES AND INDOLES WITH TRANS-3,5‐DIHYDROPEROXY‐3,5‐DIMETHYL‐1,2‐DIOXOLANE

2014 ◽  
Vol 10 (8) ◽  
pp. 3088-3096 ◽  
Author(s):  
Davood Azarifar ◽  
Maryam Golbaghi ◽  
Mahtab Pirveisian ◽  
Zohreh Najminejad
Keyword(s):  
Room Temperature ◽  
Reaction Times ◽  
Sodium Thiocyanate ◽  
Oxidative Potential ◽  
Mild Conditions ◽  
In Situ Generation

Oxidative potential of trans‐3,5‐dihydroperoxy‐3,5‐dimethyl‐1,2‐dioxolane (DHPODMDO) has been explored in the facile thiocyanation of anilines and indoles through the efficient and in situ generation of SCN+ ion from sodium thiocyanate. The reactions proceed with regioselectivity under mild conditions at room temperature to afford the respective thiocyanate derivatives in excellent yields and low reaction times.

scholarly journals Routes involving no free C2 in a DFT-computed mechanistic model for the reported room-temperature chemical synthesis of C2.

2021 ◽  
Author(s):  
Henry Rzepa
Keyword(s):  
Chemical Synthesis ◽  
Gas Phase ◽  
Room Temperature ◽  
Mechanistic Model ◽  
Reaction Times ◽  
Carbon Chain ◽  
Isotopic Substitution ◽  
Ambient Temperatures ◽  
Mild Conditions ◽  
Displacement Reactions

<p>Recent lively debates about the nature of the quadruple bonding in the diatomic species C<sub>2</sub> have been heightened by recent suggestions of molecules in which carbon may be similarly bonded to other elements. The desirability of having methods for generating such species at ambient temperatures and in solution in order to study their properties may have been realized by a recent report of the first chemical synthesis of free C<sub>2</sub> itself under mild conditions. The method involved unimolecular fragmentation of an alkynyl zwitterion<b> 2</b> as generated from the precursor <b>1</b>, resulting in production and then trapping of free C<sub>2</sub> at ambient temperatures rather than the high temperature gas phase methods normally employed for C<sub>2</sub> generation. Here, alternative mechanisms are proposed for this reaction based on DFT calculations involving bimolecular 1,1- or 1,2-iodobenzene displacement reactions from <b>2</b> directly by galvinoxyl radical, or hydride transfer from 9,10-dihydroanthracene to <b>2</b>. These mechanisms result in the same trapped products as observed experimentally, but unlike that involving unimolecular generation of free C<sub>2</sub>, exhibit calculated free energy barriers commensurate with the reaction times observed at room temperatures. The relative energies of the transition states for 1,1 <i>vs</i> 1,2 substitution provide a rationalisation for the observed isotopic substitution patterns. The same mechanism also provides an energetically facile path to polymeric synthesis of carbon rich species by extending the carbon chain attached to the iodonium group, eventually resulting in formation of amorphous carbon and discrete molecules such as C<sub>60</sub>.</p><div><div><p><br></p></div></div>

Imidazole-induced self-assembly of polyoxovanadate cluster organic framework for efficient Knoevenagel condensation under mild conditions

CrystEngComm ◽  
2020 ◽  
Vol 22 (24) ◽  
pp. 4147-4153 ◽  
Author(s):  
Ming-Yu Dou ◽  
Dan-Dan Zhong ◽  
Xian-Qiang Huang ◽  
Guo-Yu Yang
Keyword(s):  
Catalytic Activity ◽  
Self Assembly ◽  
Room Temperature ◽  
Knoevenagel Condensation ◽  
Solvent Free ◽  
Mild Conditions ◽  
Highly Efficient ◽  
Organic Framework

Three new polyoxovanadates have been made, one of them displays highly efficient heterogeneous solvent-free catalytic activity and excellent recyclability in the Knoevenagel condensation at room temperature.

An approach to highly efficient reduction of β-enamino esters: A convenient synthesis of β-amino esters

2019 ◽  
Vol 43 (5-6) ◽  
pp. 196-200
Author(s):  
Xingxian Zhang ◽  
Nengju Mi ◽  
Hongtao Liu ◽  
Yingshuai Liu
Keyword(s):  
Amino Esters ◽  
Mild Conditions ◽  
Highly Efficient ◽  
Efficient Reduction ◽  
Convenient Synthesis ◽  
Short Time

Chemoselective reduction of β-enamino esters with NaBH(OAc)3promoted by MgI2etherate affords the corresponding β-amino esters in excellent yields in a short time under mild conditions.

Alkoxymethylcyclosiloxanes - new efficient precursors of crystalline (CH3SiO3/2)8 silsesquioxane and polymethyl silsesquioxanes

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Anna Kowalewska ◽  
Krystyna Rózga-Wijas ◽  
Mirosław Handke
Keyword(s):  
Solvent Effect ◽  
Room Temperature ◽  
Condensation Process ◽  
Simple Method ◽  
Hydrolytic Condensation ◽  
Mild Conditions ◽  
Highly Efficient ◽  
Tetrabutylammonium Fluoride ◽  
Substantial Degree

AbstractA new, highly efficient and very simple method for the synthesis of pure octahedral methylsilsesquioxanes (CH3SiO3/2)8, from cyclic 2,4,6,8-tetraalkoxy- 2,4,6,8-tetramethylsiloxane, was developed. We have found that T8Me can be synthesized from a mixture of alkoxymethylcyclosiloxane isomers in the hydrolytic condensation process, utilizing an ionic catalyst - tetrabutylammonium fluoride (TBAF). The reaction was carried out under very mild conditions, at room temperature, in a variety of solvents of different polarity. A substantial solvent effect was observed. THF helped in the formation of pure T8Me, whereas in other solvents mixtures of T8Me and poly(methylsilsesquioxanes) (PMQS) of substantial degree of regularity, were obtained.

scholarly journals SbCl3-Catalyzed conversion of ketones and aldehydes into gem-dihydroperoxides (DHPs) with 30% H2O2

2015 ◽  
Vol 11 (5) ◽  
pp. 3547-3553 ◽  
Author(s):  
Davood Azarifar ◽  
Boshra Mahmoudi ◽  
Kaveh Khosravi
Keyword(s):  
Present Method ◽  
Room Temperature ◽  
Reaction Times ◽  
Experimental Procedure ◽  
Mild Conditions ◽  
Efficient Conversion ◽  
High Yields ◽  
Catalyzed Oxidation

A simple and efficient conversion of ketones and aldehydes into corresponding gem-dihydroperoxides (DHPs) has been developed by SbCl3-catalyzed oxidation with 30% H2O2 at room temperature. The reactions proceeded smoothly under mild conditions at room temperature. Simple experimental procedure, use of inexpensive and non-toxic catalyst, high yields and low reaction times are the main merits of the present method.

Brønsted Acid-Catalysed Allylic Amination of 1-(2-Aminoaryl)prop-2-en-1-ols to 1,2-Dihydroquinolines

2018 ◽  
Vol 71 (9) ◽  
pp. 673 ◽  
Author(s):  
David Philip Day ◽  
Stuart Adam Henry ◽  
Yichao Zhao ◽  
Jianwen Jin ◽  
Guy James Clarkson ◽  
...  
Keyword(s):  
Room Temperature ◽  
Trifluoromethanesulfonic Acid ◽  
Catalyst Loading ◽  
Synthetic Method ◽  
Bronsted Acid ◽  
Allylic Amination ◽  
Mild Conditions ◽  
Highly Efficient ◽  
Brönsted Acid ◽  
Wide Range

A highly efficient synthetic method to prepare 1,2-dihydroquinolines that relies on trifluoromethanesulfonic acid (TfOH)-catalysed allylic amination of 1-(2-aminoaryl)prop-2-en-1-ols is described. Achieved at a catalyst loading of 0.01 mol-% under mild conditions at room temperature, the reaction was found to be robust, with a wide range of substitution patterns tolerated. The corresponding N-heterocyclic adducts were obtained in good to excellent yields of 45–93 %.

Convenient Synthesis of (R)-3-(Boc-amino)piperidine and (R)-3-(Boc-amino)azepane

Synthesis ◽  
2021 ◽  
Author(s):  
Renat Kadyrov ◽  
Oleg L. Tok
Keyword(s):  
Room Temperature ◽  
Hydrogenation Catalysts ◽  
Mild Conditions ◽  
Convenient Synthesis

(R)-3-(Boc-amino)piperidine and (R)-3-(Boc-amino)azepane prepared in 2 steps starting from D-lysine and D-ornithine. In the key-step, N-Boc protected 3-aminolactams were converted into imido esters by O-alkylation and then hydrogenated to amines, under mild conditions (5 bar H2, room temperature) and without isolation, over standard hydrogenation catalysts (5% Pt/C).

Application of metalloporphyrins as new catalysts for the efficient, mild and regioselective synthesis of quinoxaline derivatives

2010 ◽  
Vol 14 (12) ◽  
pp. 1052-1058 ◽  
Author(s):  
Khosro Mohammadi ◽  
Alireza Hasaninejad ◽  
Mahmud Niad ◽  
Mojtaba Najmi
Keyword(s):  
Room Temperature ◽  
Reaction Times ◽  
Regioselective Synthesis ◽  
Central Metal ◽  
Highly Efficient ◽  
Quinoxaline Derivatives ◽  
Porphyrin Core ◽  
Green Procedure

A simple, highly efficient and green procedure for the condensation of aryl and alkyl 1,2-diamines with α-diketones in the presence of catalytic amounts of metalloporphyrins at room temperature is described. Using this method, quinoxaline derivatives as biologically interesting compounds are produced in high to excellent yields and short reaction times. In this report, the effects of central metal in porphyrin core and substituents on tetraphenylporphyrin skeleton have been studied.

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