100723-77-1Relevant articles and documents
Efficient preparation of polyfunctional indoles via a zinc organometallic variation of the Fischer indole synthesis
Zhang, Zhi-Guang,Haag, Benjamin A.,Li, Jin-Shan,Knochel, Paul
, p. 23 - 29 (2011)
Functionalized organozinc reagents readily react with various aryldiazonium salts furnishing regioselectively polyfunctional indoles after heating with microwave irradiation. This new organometallic variation of the Fischer indole synthesis tolerates a wide range of functional groups and can be readily scaled up. Georg Thieme Verlag Stuttgart · New York.
A Convenient Modification of the Fischer Indole Synthesis with a Solid Acid
Chandrasekhar, Sosale,Mukherjee, Somnath
, p. 1018 - 1022 (2015)
(Chemical Equation Presented). A new one-pot version of the titled reaction involves heating a mixture of a carbonyl compound, a phenylhydrazine, and the cation exchange resin Amberlite IR 120 in refluxing ethanol. A variety of enolizable aldehydes, and ketones and several substituted phenylhydrazines could thus be converted to the corresponding indoles in excellent yields (70-88%). Reaction times were typically 6-10 h, with the resin being then filtered off and the product isolated after minimal workup.
Fischer indole synthesis with organozinc reagents
Haag, Benjamin A.,Zhang, Zhi-Guang,Li, Jin-Shan,Knochel, Paul
, p. 9513 - 9516 (2010)
Updated classic: Primary and secondary alkylzinc reagents add to various aryldiazonium salts leading regioselectively to polyfunctional indoles by means of a [3,3]-sigmatropic shift and subsequent aromatization. This organometallic variation of the Fischer indole synthesis tolerates a wide range of functional groups and displays absolute regioselectivity. Copyright
Annulation of Indoles with 1,n-Dibromoalkanes by a Pd(II)-Catalyzed and Norbornene-Mediated Reaction Cascade
Bach, Thorsten,Henkel, Michael
, p. 1231 - 1238 (2020)
Employing 1,3-dibromopropane, 1,4-dibromobutane, and 1,5-dibromopentane as biselectrophiles, the annulation of indoles was probed in the presence of PdCl 2 (MeCN) 2 as a catalyst and norbornene as a transpositional ligand. Ring formation to a five-membered ring was observed at positions C2 and N, while annulation of a six-membered ring occurred at positions C2 and C3. The latter cascade process was successfully applied to the direct synthesis of 1,2,3,4-tetrahydrocarbazoles from indoles (11 examples, 31-68% yield). Seven-membered-ring annulation was feasible by an initial coupling at positon C2 followed by alkylation at C3.
Process for synthesizing [b]-cycloindole derivatives
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Paragraph 0039-0041, (2021/04/17)
The invention discloses a method for synthesizing [b]-cyclized indole derivatives. The method comprises the steps as follows: alkylation ring-closing domino reactions at C2 and C3 sites of indole aresequentially realized with a one-pot process under the action of alkali and a palladium catalyst with norbornene as a transient guide medium and dihaloalkane as an alkylation reagent, and the [b]-cyclized indole derivatives are effectively synthesized. The method has mild conditions, commercially available indole is directly used as a substrate, a pre-functionalization process is omitted, reactionsteps are reduced, the atom economy is higher, simple indole micromolecular structures are modified, and the [b]-cyclized indole derivatives can be further applied to medicine or total synthesis research and the like and have higher potential value and broad application prospects in medicinal chemistry and other fields.
PYRIDINE BASED IONIC FLUORIDE FOR CATALYZING INDOLE AND TETRAZOLE FORMATION
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Paragraph 0031; 0115; 0116; 0121, (2020/01/02)
A pyridine based ionic liquid with a fluoride counter anion which catalyzes Fischer indole reaction and click chemistry. Methods of preparing the ionic liquid, and methods of utilizing the ionic liquid as a catalyst to synthesize indoles/indolenines and tetrazoles are also provided.
