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1.
Chem Asian J ; : e202400711, 2024 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-39176435

RESUMO

A direct ortho-Csp2-H acylalkylation of 2-aryl-2,3-dihydrophthalazine-1,4-diones with unsubstituted and substituted allyl alcohols is achieved in high yields through Rh(III)-catalyzed C-H bond activation process. The additional employment of Cu(OAc)2.2H2O as an oxidant detour the reaction towards [4+1] annulation, producing 13-(2-oxopropyl)-13H-indazolo[1,2-b]phthalazine-6,11-diones in moderate yields. Interestingly, Lawesson's reagent-mediated conditions accomplished intramolecular cyclization in ortho-(formylalkylated)-2,3-dihydrophthalazine-1,4-diones to produce diazepino[1,2-b]phthalazine-diones in moderate yields. Furthermore, allyl alcohol showcased distinct reactivity in presence of different additives to produce ortho-allylated, oxidative and non-oxidative [4+2] annulated products.

2.
Chem Commun (Camb) ; 60(59): 7622-7625, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-38957144

RESUMO

Pyridyloxy-directed Ir(III)-catalyzed diacylmethylation of protected tyrosines was achieved with alkyl and (hetero)aryl sulfoxonium ylides, furnishing tyrosine-based unnatural amino acids in good yields. Furthermore, the late stage exemplification of the strategy was successfully accomplished in tyrosine-containing dipeptides, tripeptides and tetrapeptides in moderate yields. This methodology is distinguished by its site-selectivity, tolerance of sensitive functional groups, scalability, and retention of the chiral configuration for tyrosine motifs.


Assuntos
Irídio , Peptídeos , Tirosina , Irídio/química , Catálise , Tirosina/química , Metilação , Peptídeos/química , Compostos de Sulfônio/química , Estrutura Molecular
3.
Org Lett ; 25(42): 7673-7677, 2023 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-37853547

RESUMO

Pyridyloxy-directed Rh(III)-catalyzed regioselective C3Ar-H alkenylation of protected tyrosines was achieved with N-aryl and N-alkyl maleimides, furnishing a series of maleimide-appended tyrosine-based unnatural amino acids in good yields. Further, the late-stage exemplification of the strategy was successfully accomplished on tyrosine-containing dipeptides, tripeptides, and tetrapeptides in moderate reactivity. Also, the chemical applications of the strategy were successfully executed toward nailing tyrosine with other amino acids via a maleimide linker and intramolecular hydroarylation to produce tyrosine-centered stapled products and succinimide-glued macrocyclized products, respectively.


Assuntos
Ródio , Estrutura Molecular , Ródio/química , Tirosina , Aminoácidos , Maleimidas/química , Peptídeos , Catálise
4.
Org Biomol Chem ; 21(33): 6719-6729, 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37555287

RESUMO

A Pd(II)-catalyzed strategy for the diastereo- and regioselective (hetero)arylation of unactivated C(sp3)-H bonds in bile acids is accomplished with aryl and heteroaryl iodides under solvent-free conditions using the 8-aminoquinoline auxiliary as a directing group. This methodology demonstrated excellent functional group tolerance with respect to aryl/heteroaryl iodides on O-protected N-(quinolin-8-yl)cholyl/deoxycholyl amides to afford ß-C(sp3)-H (hetero)arylated products in good-to-excellent yields. Moreover, the 8-aminoquinoline (AQ) auxiliary can easily be removed to obtain modified bile acids.

5.
Org Biomol Chem ; 20(23): 4753-4764, 2022 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-35616276

RESUMO

Ru(II)-catalyzed strategies were developed for the [4 + 1] and [4 + 2] oxidative coupling between N-aryl-2,3-dihydrophthalazine-1,4-diones and 1,4-benzoquinones, achieving spiro-indazolones and fused-cinnolines, respectively. Mild, aerobic and external oxidant-free conditions, as well as the use of a ruthenium catalyst for such (spiro)annulative strategies with quinones over reported Rh/Ir-catalyts, underline the rewards of the disclosed protocols.


Assuntos
Rutênio , Compostos de Espiro , Catálise , Compostos Heterocíclicos com 2 Anéis , Estrutura Molecular , Quinonas
6.
J Org Chem ; 87(5): 3701-3706, 2022 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-35077162

RESUMO

A tender-hearted Pd(II)-catalyzed C-H activation of 1-arylindazolones followed by an oxidative [4 + 2] annulation reaction has been accomplished, engaging allenoates as annulating partners. Using this strategy, two different regioisomeric forms of cinnoline-fused indazolones possessing internal and exocyclic double bonds were synthesized in acetic acid and dioxane, respectively. Mild and aerobic conditions, avoiding the use of any metal-oxidant, highlights the rewards of this oxidative annulation protocol.


Assuntos
Compostos Heterocíclicos com 2 Anéis , Paládio , Catálise , Paládio/química
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