Acid-Mediated Denitrogenation/Rearrangement/Coupling of ­Benzyl Azides with Triazolyl-Substituted Cycloalkanones

Synlett ◽  
2020 ◽  
Vol 31 (04) ◽  
pp. 388-392
Author(s):  
Ying Fu ◽  
Zhengyin Du ◽  
Yang Che ◽  
Rui Wang
Keyword(s):  
Reaction Mechanism ◽  
Efficient Method ◽  
Organic Molecules ◽  
Cyclic Ketone ◽  
Triflic Acid ◽  
Cyclic Ketones ◽  
Electrophilic Attack ◽  
Nitrogen Elimination

Organic molecules containing α-triazolyl or β-amino cyclic ketone fragments have been individually proven to show good bioactivities and to be useful in asymmetric and pharmaceutical syntheses. A triflic acid-promoted simple and efficient method for the synthesis of unsymmetrical α-triazolyl-α′-(aminomethyl)cycloalkanones from benzyl azides and α-triazolylcycloalkanones has been developed. A series of unsymmetrical α,α′-disubstituted cycloalkanones were obtained with high syn-diastereoselectivity and up to 82% yield. Examination of the reaction mechanism showed that the benzyl azides undergo protonation, nitrogen elimination, rearrangement, and electrophilic attack by the enol forms of the cyclic ketones.

ChemInform Abstract: THE REACTION OF ORGANIC MOLECULES ON SOLID SURFACES. 2. AN EFFICIENT METHOD FOR THE PREPARATION OF DEUTERATED ALUMINA

1985 ◽  
Vol 16 (31) ◽  
Author(s):  
K. GAETANO ◽  
R. M. PAGNI ◽  
G. W. KABALKA ◽  
P. BRIDWELL ◽  
E. WALSH ◽  
...  
Keyword(s):  
Efficient Method ◽  
Organic Molecules ◽  
Solid Surfaces

Intramolecular Cycloaddition Approach to Fused Pyrazoles: Access to 4,5-Dihydro-2H-pyrazolo[4,3-c]quinolines, 2,8-Dihydroindeno[2,1-c]pyrazoles, and 4,5-Dihydro-2H-benzo[e]indazoles

Synthesis ◽  
2017 ◽  
Vol 50 (07) ◽  
pp. 1511-1520 ◽  
Author(s):  
Chinmay Chowdhury ◽  
Moumita Jash ◽  
Bimolendu Das ◽  
Suparna Sen
Keyword(s):  
Reaction Mechanism ◽  
Dft Calculations ◽  
Functional Groups ◽  
Efficient Method ◽  
Diazo Compound ◽  
Dipolar Cycloaddition ◽  
Reaction Sequence ◽  
Intramolecular Cycloaddition ◽  
Aromatic Substrate ◽  
Fused Pyrazoles

A straightforward and efficient method for the synthesis of pyrazoles fused with 1,2,3,4-tetrahydroquinoline, 2,3-dihydro-1H-indene­, or 1,2,3,4-tetrahydronaphthalene involves the formation of the tosylhydrazone from an aromatic substrate carrying aldehyde and acetylenic functionalities at appropriate positions, followed by base-promoted generation of the diazo compound and subsequent intramolecular 1,3-dipolar cycloaddition. A number of functional groups were found to be compatible for this reaction sequence and yields were moderate to very good (44–95%). A plausible reaction mechanism supported by DFT calculations has been provided to explain the formation of products.

scholarly journals Synthesis of Pyrroles Through the CuH-Catalyzed Coupling of Enynes and Nitriles

2020 ◽  
Author(s):  
Yujing Zhou ◽  
Lin Zhou ◽  
Luke T. Jesikiewicz ◽  
Peng Liu ◽  
Stephen L. Buchwald
Keyword(s):  
Density Functional Theory ◽  
Reaction Mechanism ◽  
Dft Calculations ◽  
Efficient Method ◽  
Density Functional ◽  
Coupling Reaction ◽  
Copper Hydride ◽  
Reductive Coupling ◽  
Functional Theory ◽  
Subsequent Cyclization

<p>Herein, we describe an efficient method to prepare polysubstituted pyrroles via a copper-hydride (CuH)-catalyzed enyne-nitrile coupling reaction. This protocol accommodates both aromatic and aliphatic substituents and a broad range of functional groups, providing a variety of N-H pyrroles in good yields and with high regioselectivity. We propose that the Cu-based catalyst promotes both the initial reductive coupling and subsequent cyclization steps. Density functional theory (DFT) calculations were performed to elucidate the reaction mechanism.</p>

scholarly journals One-Pot Synthesis of (Z)-β-Halovinyl Ketones via the Cascade of Sonogashira Coupling and Hydrohalogenation

2021 ◽  
Vol 8 ◽  
Author(s):  
Fa-Jie Chen ◽  
Zhenguo Hua ◽  
Jianhui Chen ◽  
Jiajia Chen ◽  
Daesung Lee ◽  
...  
Keyword(s):  
Efficient Method ◽  
Room Temperature ◽  
Copper Catalyst ◽  
High Yield ◽  
Sonogashira Coupling ◽  
Terminal Alkynes ◽  
Acid Chlorides ◽  
Triflic Acid ◽  
One Pot

Herein, we report an efficient method for the synthesis of (Z)-β-halovinyl ketones through a one-pot Sonogashira coupling and hydrohalogenation reaction promoted by palladium-copper catalyst and Brønsted acid. The ynone intermediates are generated in situ from readily available acid chlorides and terminal alkynes at room temperature, which are directly converted to (Z)-β-halovinyl ketones by treating with triflic acid. This method avoids the use of an external halogen source and features broad substrate scope, high yield, and good to excellent stereoselectivity.

An efficient method in manipulating CO coverage dissociated from small organic molecules on the Pt electrode surface

2017 ◽  
Vol 47 (5) ◽  
pp. 647-654
Author(s):  
Wen-Jie Chen ◽  
Chun-Mei Xiao ◽  
Yi-Ting Chen ◽  
Xue-Jiao Sun ◽  
Miao-Qiong Xu ◽  
...  
Keyword(s):  
Efficient Method ◽  
Electrode Surface ◽  
Organic Molecules ◽  
Pt Electrode ◽  
Small Organic Molecules

Equilibrium 2H/1H fractionation in organic molecules: III. Cyclic ketones and hydrocarbons

2013 ◽  
Vol 107 ◽  
pp. 82-95 ◽  
Author(s):  
Ying Wang ◽  
Alex L. Sessions ◽  
Robert J. Nielsen ◽  
William A. Goddard
Keyword(s):  
Organic Molecules ◽  
Cyclic Ketones

scholarly journals An Improved, Highly Efficient Method for the Synthesis of Bisphenols

2011 ◽  
Vol 8 (4) ◽  
pp. 2016-2019 ◽  
Author(s):  
L. S. Patil ◽  
V. S. Suryawanshi ◽  
O. B. Pawar ◽  
N. D. Shinde
Keyword(s):  
Efficient Method ◽  
High Purity ◽  
Cetyltrimethylammonium Chloride ◽  
Efficient Synthesis ◽  
Cyclic Ketones ◽  
Substituted Phenols ◽  
Mercaptopropionic Acid ◽  
Highly Efficient

An efficient synthesis of bisphenols is described by condensation of substituted phenols with corresponding cyclic ketones in presence of cetyltrimethylammonium chloride and 3-mercaptopropionic acid as a catalyst in extremely high purity and yields.

scholarly journals Nitric oxide induces Zn2+ release from metallothionein by destroying zinc–sulphur clusters without concomitant formation of S-nitrosothiol

1999 ◽  
Vol 344 (1) ◽  
pp. 253-258 ◽  
Author(s):  
Charuvila T. ARAVINDAKUMAR ◽  
Jan CEULEMANS ◽  
Marc DE LEY
Keyword(s):  
Nitric Oxide ◽  
Reaction Mechanism ◽  
Strictly Anaerobic ◽  
Common Belief ◽  
Anaerobic Conditions ◽  
Electrophilic Attack ◽  
Subsequent Formation ◽  
Aerobic Conditions ◽  
Percentage Loss ◽  
Zinc Release

The reaction of nitric oxide (NO) with metallothionein (MT) has been investigated at neutral pH under strictly anaerobic conditions. It is observed that NO mediates zinc release from MT by destroying zinc-sulphur clusters, but that it does not by itself S-nitrosylate MT in contrast to common belief. Zinc release and loss of thiolate groups under anaerobic conditions is found to be much slower than under aerobic conditions. The observed percentage loss of Zn2+ and thiolate groups after 3 h of NO treatment are 62 and 39%, respectively. The reaction of NO with cysteine is reinvestigated and it is found that cysteine is quantitatively converted to cystine after 5 min of NO treatment at pH 7.3. At lower pH, a much lower rate of conversion is observed confirming the base-catalysed nature of the reaction of NO with thiols. On the basis of these results, a reaction mechanism involving electrophilic attack of NO on thiolate groups and subsequent formation of a nitrogen-centred radical, MTSN•OH, as intermediate is proposed for the reaction of NO with MT that leads to zinc release.

Synthesis of substituted 4-azaisoindoles — New tacrine analogues

2007 ◽  
Vol 85 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Henri Bekolo ◽  
Gilbert Kirsch
Keyword(s):  
Reaction Mechanism ◽  
Cyclic Ketones ◽  
New Class

The regioselective Friedländer reaction of 3-amino-4-cyanopyrroles with a series of cyclic ketones has enabled the first reported synthesis of substituted 4-azaisoindoles. Structurally, this new class of compounds stands for the first reported 4-azaisoindole tacrine analogues. A reaction mechanism for the formation of the reported 4-azaisoindoles is proposed.Key words: 4-azaisoindoles, tacrine, Friedländer reaction, pyrroles, mechanism.

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