نتایج جستجو برای: cyclization of time

تعداد نتایج: 21267950  

2017
Yuanze Wang Pravin Patil Katarzyna Kurpiewska Justyna Kalinowska-Tluscik Alexander Dömling

Isocyanide-based multicomponent reactions (IMCR) are by far the most versatile reactions that can construct relatively complex molecules by one-pot synthesis. More importantly, the development of post IMCR modifications significantly improves the scaffold's diversity. Here, we describe the use of N-Boc protected hydrazine together with α-amino acid derived isocyanides in the Ugi tetrazole react...

Journal: :European Journal of Organic Chemistry 2022

We have developed a Ni-catalyzed cascade cyclization/Negishi-coupling reaction for the formation of pyrrolidines and pyrrolidinones starting from N-protected allylamines acrylamides which contain redox active ester group. The provides two C-C bonds in single operation takes place with both alkylzinc arylzinc bromides as nucleophiles. Activation RAE by low valent Ni complexes involving radical p...

Journal: :Journal of Synthetic Organic Chemistry, Japan 1961

Journal: :NIPPON KAGAKU KAISHI 1973

Journal: :Organic & biomolecular chemistry 2006
Marco Angeli Marco Bandini Andrea Garelli Fabio Piccinelli Simona Tommasi Achille Umani-Ronchi

A practical catalytic approach to the synthesis of 4-substituted 1,2,3,4-tetrahydro-beta-carbolines (THBCs, 1) and 1,2,3,9-tetrahydropyrano[3,4-b]indoles (2) via InBr3-catalyzed intramolecular Friedel-Crafts (F-C) cyclization is described. The use of cross-metathesis reaction represents a direct route to the cyclization precursors and the use of InBr3 (5 mol%) allowed polycyclic indole compound...

Maryam Rastroshan Rashid Badri Soheil Sayyahi, Vali Zare-Shahabadi,

In this study, aluminosilicate MCM-41 has been found to be an efficient catalyst for reaction betweendifferent benzaldehyde derivatives and 5,5-dimethyl-1,3-cyclohexanedione to give open chain analogue of1,8-dioxo-octahydroxanthene in excellent yields. No evidence for the formation of cyclization products wasobserved. The catalyst can be used several times after recovery.

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده علوم انسانی 1390

one very decisive factor in students’ academic destiny is the result they get at final term examinations. because of its importance, both students and teachers are curiously anxious about them. as normally it is the case, these final term tests are prepared hurriedly in short time by teachers which result in students’ dissatisfaction, complaining on how the test was different from their expecta...

Journal: :Journal of Biological Chemistry 1940

Journal: :Chemistry Journal of Moldova 2006

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