Surprising selectivity in the transformation of dimethoxy azaindoles

Gesenberg, Kirsten D.; Deshpande, Prashant P.; Pullockaran, Annie; Xu, Feng; Wu, Dedong; Gao, Qi; Pathirana, Charles; Castoro, John A.; Soundararajan, Ν.; Staab, Andrew J.

doi:10.1016/j.tetlet.2007.02.076

Cited by 9 publications

(3 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a last reaction (Scheme 3), we cleaved the methoxy ether group in C-5 of the azaindoles 18 and 22 with in situ formed TMSI (from TMSCl and NaI). 20 The two final derivatives 27 and 28 were isolated after only 2 h with respectively 52 and 63% of yields.…”

mentioning

confidence: 98%

Synthesis and biological evaluation of 2,3-bis(het)aryl-4-azaindole derivatives as protein kinase inhibitors

Pin¹,

Buron²,

Saab³

et al. 2011

Med. Chem. Commun.

View full text Add to dashboard Cite

International audienceThe synthesis of several novel 4-azaindoles was carried out by novel Fischer reaction which offers as a main advantage, the synthesis of the bisfunctionalized 4-azaindolic building block in one step. The final compounds were evaluated on a panel of 5 kinases in order to evaluate their selectivity and on 7 cancer cell lines to determine their cytotoxic effects. RAF-1 and DYRK1A inhibitions were found, docking studies explain fully the results

show abstract

mentioning

confidence: 98%

Synthesis and biological evaluation of 2,3-bis(het)aryl-4-azaindole derivatives as protein kinase inhibitors

Pin¹,

Buron²,

Saab³

et al. 2011

Med. Chem. Commun.

View full text Add to dashboard Cite

show abstract

“…We then explored the regioselective demethylation of 2,3,4-trimethoxycarbazole 11 to generate 2hydroxy-3,4-dimethoxycarbazole 19 (Table 4). The use of concentrated hydrochloric acid [ 16 ] led to the formation of a mixture of the desired hydroxycarbazole 19, 3-hydroxycarbazole 20, and 4hydroxycarbazole 21 with 63% recovery of 11 (entry 1). A combination of trimethylsilyl chloride (TMSCl) and sodium iodide [17] improved the yield of the desired carbazole 19 (23%); however, regioisomers 20 and 21 were also observed in 13% and 9% yields, respectively (entry 2).…”

Section: Resultsmentioning

confidence: 99%

Gram-Scale Total Synthesis of Carbazomycins A–D

Feng,

Mori,

Okano

2024

Preprint

View full text Add to dashboard Cite

Gram-scale total synthesis of carbazomycins A–D is described. The total synthesis of carbazomycin A was achieved in 44% overall yield over six steps from symmetrical 5-chloro-1,2,3-trimethoxybenzene. The key aryne-mediated carbazole-formation and methylation steps provided the multiply substituted carbazole. The regioselective demethylation of the trimethoxycarbazole was performed using boron trichloride. Thereafter, the phenolic hydroxy group was converted into the methyl group to provide carbazomycin A. Subsequent installation of the methoxy group realized the total synthesis of carbazomycin D. Regioselective demethylation was performed using 1-dodecanethiol, effecting the conversions of carbazomycins A and D into carbazomycins B and C, respectively.

show abstract

“…Several reagents are known for the deprotection of methyl ethers: BBr 3 , [32] ethanethiol or its odorless version, [33] ISiMe 3 [34] and concentrated hydrochloric acid. [35] The choice of this last reagent did not appear relevant as the ester group might be cleaved simultaneously or instead the methoxy group of 8a. Upon treatment of this azaindole with trimethylsilyl iodide, the expected product 7a was obtained in 24 % yield (Scheme 10).…”

Section: Preparation Of C(2)-substituted Azaindolesmentioning

confidence: 99%

A Journey through Hemetsberger–Knittel, Leimgruber–Batcho and Bartoli Reactions: Access to Several Hydroxy 5‐ and 6‐Azaindoles

Radix

Hallé

Mahiout

et al. 2022

Helvetica Chimica Acta

View full text Add to dashboard Cite

This work is dedicated to Prof. E. Peter Kündig for his 75th birthday and for his mentorship for three of us (S. R., Z. M. and T. L.) when we were post-doctoral research assistants in his laboratory.The preparation of various 5-and 6-azaindoles, heterocyclic structures that are frequently part of molecules in clinical development, and their monohydroxy analogues were described. Different strategies, relying on the de novo pyrrole ring formation, were investigated and, thanks to Hemetsberger-Knittel, Bartoli and Leimgruber-Batcho approaches, 4-and 7-monohydroxy 5-and 6-azaindoles were obtained. The crucial introduction of the oxygen atom was carried out from halogen derivatives, using nucleophilic substitution reactions under basic conditions with or without a copper catalyst. Some preliminary oxidation reactions have shown that it was yet not possible to synthesize the azaquinone indole structure from monohydroxy azaindole, using molecular oxygen in the presence of salcomine as a catalyst.

show abstract

Surprising selectivity in the transformation of dimethoxy azaindoles

Cited by 9 publications

References 10 publications

Synthesis and biological evaluation of 2,3-bis(het)aryl-4-azaindole derivatives as protein kinase inhibitors

Synthesis and biological evaluation of 2,3-bis(het)aryl-4-azaindole derivatives as protein kinase inhibitors

Gram-Scale Total Synthesis of Carbazomycins A–D

A Journey through Hemetsberger–Knittel, Leimgruber–Batcho and Bartoli Reactions: Access to Several Hydroxy 5‐ and 6‐Azaindoles

Contact Info

Product

Resources

About