نتایج جستجو برای: β enaminones

تعداد نتایج: 177653  

Journal: :Chemistry 2013
Nathan B Bennett Douglas C Duquette Jimin Kim Wen-Bo Liu Alexander N Marziale Douglas C Behenna Scott C Virgil Brian M Stoltz

Eeny, meeny, miny ... enaminones! Lactams and imides have been shown to consistently provide enantioselectivities substantially higher than other substrate classes previously investigated in the palladium-catalyzed asymmetric decarboxylative allylic alkylation. Several new substrates have been designed to probe the contributions of electronic, steric, and stereoelectronic factors that distingui...

2006
Renata Jakše David Bevk Amalija Golobič Jurij Svete Branko Stanovnik

Recently, a series of alkyl 2-substituted 3-(dimethylamino)prop-2-enoates and related enaminones have been prepared as versatile reagents for the preparation of various dehydroalanine derivatives, heterocyclic systems, and natural product analogues. In extension, chiral cyclic enamino lactams and lactones, derived from α-amino acids and (+)-camphor have been used in the synthesis of functionali...

Journal: :Molecules 2011
Sayed M Riyadh

Novel N-arylpyrazole-containing enaminones 2a,b were synthesized as key intermediates. Reactions of 2a,b with active methylene compounds in acetic acid in the presence of ammonium acetate afforded substituted pyridine derivatives 5a-d. Enaminones 2a,b also reacted with aliphatic amines such as hydrazine hydrate and hydroxylamine hydrochloride to give bipyrazoles 8a,b and pyrazolylisoxazoles 9a,...

Journal: :Beilstein Journal of Organic Chemistry 2008
Joseph P Michael Claudia Accone Charles B de Koning Christiaan W van der Westhuyzen

BACKGROUND Prior work from these laboratories has centred on the development of enaminones as versatile intermediates for the synthesis of alkaloids and other nitrogen-containing heterocycles. In this paper we describe the enantioselective synthesis of indolizidine and quinolizidine analogues of bicyclic amphibian alkaloids via pyrrolidinylidene- and piperidinylidene-containing enaminones. RE...

2009
Stefan Knauer Markus Weymann Horst Kunz

N-Galactopyranosyland N-glucopyranosyl imines of aliphatic, aromatic and heteroaromatic aldehydes react with 1-methoxy-3-trimethylsilyloxy-1,3-butadiene in a domino Mannich-Michael reaction cascade to give 2-substituted 5,6-dehydro-piperidin-4-ones with high diastereoselectivity. Treatment of these cyclic enaminones with N-bromo-succinimide yields the corresponding 2-substituted 5-bromo-5,6-deh...

Journal: :Molecules 2008
Abdul-aziz Alnajjar Mervat Mohammed Abdelkhalik Amal Al-Enezi Mohamed Hilmy Elnagdi

The reported structures of reaction products of enaminones with malononitrile in ethanolic piperidine are revised. A novel route to 2,3-dihydropyridazine-4-carboxylic acids 4a-c via reactions of 2-cyano-5-(dimethylamino)-5-arylpenta-2,4-dienamides 8a-c with nitrous acid or with benzenediazonium chloride is reported. Compounds 8a-c are converted to 1,2-dihydropyridine-3-carboxylic acid and 1,2-d...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علامه طباطبایی 1388

عاملهای شناختی، شخصیتی و موقعیتی متعددی یافت شده است که می توانند با پرخاشگری ارتباط داشته باشند. فهم چگونگی ارتباط درونی این عاملها برای پیش بینی، سنجش، و درمان پرخاشگری زندانیانی که سابقه رفتارهای پرخاشگرانه را دارند، بسیار اساسی است. پژوهشهای قبلی نقش بالقوه ای را برای توانایی حل مساله اجتماعی بعنوان یک میانجیگر بین تکانشگری و پرخاشگری پیشنهاد کرده اند. ( موران و همکاران، 2002). علاوه بر این...

Journal: :The Journal of organic chemistry 2010
Micah J Niphakis Brandon J Turunen Gunda I Georg

Six- and seven-membered cyclic enaminones can be prepared using common, environmentally benign reagents. Amino acids are used as synthetic precursors allowing diversification and the incorporation of chirality. The key reaction in this multistep process involves deprotection of Boc-amino ynones and subsequent treatment with methanolic K(2)CO(3) to induce cyclization. A β-amino elimination side ...

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