- Switchable Synthesis of 3-Substituted 1H-Indazoles and 3,3-Disubstituted 3H-Indazole-3-phosphonates Tuned by Phosphoryl Groups
-
3-Alkyl/aryl-1H-indazoles and 3-alkyl/aryl-3H-indazole-3-phosphonates were synthesized efficiently through a 1,3-dipolar cycloaddition reaction between α-substituted α-diazomethylphosphonates and arynes under simple reaction conditions. The product distribution was controlled by the phosphoryl group, which acted both as a tuning group and a traceless group in the reaction.
- Chen, Guihua,Hu, Minglin,Peng, Yungui
-
p. 1591 - 1597
(2018/02/10)
-
- Palladium-catalyzed synthesis of indoles via ammonia cross-coupling-alkyne cyclization
-
The synthesis of indoles via the metal-catalyzed cross-coupling of ammonia is reported for the first time; the developed protocol also allows for the unprecedented use of methylamine or hydrazine as coupling partners. These Pd/Josiphos-catalyzed reactions proceed under relatively mild conditions for a range of 2-alkynylbromoarenes.
- Alsabeh, Pamela G.,Lundgren, Rylan J.,Longobardi, Lauren E.,Stradiotto, Mark
-
supporting information; experimental part
p. 6936 - 6938
(2011/08/06)
-
- METHOD OF SYNTHESIZING 1H-INDAZOLE COMPOUNDS
-
A method is provided for synthesizing 1H-indazole compounds in which aromatic carbonyl compounds are reacted with a nitrogen source to form oximes which are then converted to 1H-indazoles.
- -
-
Page/Page column 3
(2010/04/23)
-
- A practical, metal-free synthesis of 1H-Lndazoles
-
The synthesis of 1H-indazoles is achieved from o-aminobenzoximes by the selective activation of the oxime in the presence of the amino group. The reaction occurs with a variety of substituted o-aminobenzoximes using a slight excess of methanesulfonyl chloride and triethylamine at 0-23 °C and is amenable to scale-up. The synthesis of 1 H-indazoles under these conditions is extremely mild compared with previous synthetic approaches and affords the desired compounds in good to excellent yields.
- Counceller, Carla M.,Eichman, Chad C.,Wray, Brertda C.,Stambuli, James P.
-
supporting information; experimental part
p. 1021 - 1023
(2009/04/07)
-
- A VERSATILE SYNTHESIS OF SUBSTITUTED INDAZOLES
-
A four-step synthetic sequence for substituted indazoles was presented from 2-acylcyclohexane-1,3-diones via either simultaneous or stepwise dehydration and dehydrogenation of 4-substituted 4-hydroxy-4,5,6,7-tetrahydroindazoles as a key step.
- Kim, Jin Il,Kim, Byung Chul,Moon, Seung Wook,Jahng, Yurngdong
-
p. 1471 - 1478
(2007/10/02)
-
- Phase-Transfer-Catalyzed Gomberg-Bachmann Synthesis of Unsymmetrical Biarenes: A Survey of Catalysts and Substrates
-
Two problems have hindered the Gomberg-Bachmann (GB) and Pschorr reactions of arenediazonium cations: the instability of the arenediazonium salts and side reactions.Arenediazonium tetrafluoroborate and hexafluorophosphate salts can be prepared in high yield and purity and can be stored safely.Unfortunately, these salts are insoluble in most nonpolar organic solvents.Crown ether complexation or other phase-transfer (pt) catalytic methodology can ameliorate this situation, and reactions conducted by the approaches outlined herein often afforded coupling or cyclization products in high yield and corresponding purity.The use of crown ethers, quarternary 'onium salts, lipophilic carboxylic acid salts, and even the polar cosolvent acetonitrile increase the utility of the ptGB reaction dramatically.Sixty examples of couplings are reported along with an assessment of selectivities.A number of examples are also presented of phase-transfer-type Pschorr cyclizations.In the latter case, the use of potassium superoxide, KO2, is introduced to suppress indazole formation.
- Beadle, James R.,Korzeniowsky, Stephen H.,Rosenberg, David E.,Garcia-Slanga, Blanche J.,Gokel, George W.
-
p. 1594 - 1603
(2007/10/02)
-