Base-Mediated Modular Synthesis of Amino-aroyl-naphthalenes, Quinolines, and Carbazoles from 2-(Alkynyl)carbonitriles
Debanik Panda1, Shivam A Meena1, Manvi Sharma1
1Department of Chemistry, University of Delhi, Delhi, 110007, India.
Abstract:
An efficient and atom-economical modular approach for the regioselective tandem synthesis of amino(phenyl)methanone substituted polycycles and N-heterocycles from easily accessible 2-(alkynyl)nitriles under mild reaction conditions has been developed. The designed chemistry involves aza-Henry reaction and successive regioselective 6-endo-dig cyclization to afford the challenging o-benzoyl substituted 1-aminonapthalenes, 5-aminoquinolines, and 4-aminocarbazoles. The developed methodology works well with 2-(alkynyl)benzonitrile, 2-(alkynyl)nicotinonitrile, and 2-alkynyl indole-3-carbonitriles and accommodates wide functional group variation on the alkyne terminus. Other nucleophiles, e.g., 1-acetonapthone and 2-acetylpyridine, were also found suitable for this conversion, further extending the diversity of the developed chemistry.
Related Concept Videos
Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
Nucleophilic Aromatic Substitution: Elimination–Addition
Preparation of 1° Amines: Gabriel Synthesis
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
Preparation of Nitriles
Preparation of Alkynes: Alkylation Reaction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
Preparation of 1° Amines: Azide Synthesis
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...

![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)
