نتایج جستجو برای: heterocycle

تعداد نتایج: 914  

2011
Thomas Theissmann Michael Bolte

The title compound, C(21)H(18)ClN, was synthesized by an enanti-oselective Brønsted acid-catalysed transfer hydrogenation reaction. The six-membered heterocycle adopts a half-chair conformation. It has the biphenyl residue in an axial position. The two rings of the biphenyl residue are almost coplanar [dihedral angle = 2.65 (9)°]. The crystal packing is stabilized by N-H⋯Cl hydrogen bonds, whic...

2013
Adriana Cruz-Enríquez Hector J. Peinado-Guevara Viviana Reyes-Marquez Herbert Höpfl José J. Campos-Gaxiola

In the title adduct, C5H5NO·C8H12O4, the heterocycle exists in its zwitterionic form. The cyclo-hexane ring exhibits a chair conformation with the carb-oxy-lic acid groups in equatorial and axial orientations. In the crystal, mol-ecules are linked through charge-assisted O-H⋯O(-), N(+)-H⋯O(-) and N(+)-H⋯O hydrogen bonds, and an additional series of C-H⋯O contacts, giving a pleated two-dimension...

2010
Fang-Fang Jian Zhi-Peng Ni

In the title compound, C(22)H(23)NO(4)·C(2)H(6)O, the pyridyl ring is aligned at 89.39 (2) and 87.41 (2)° with respect to the benzene rings, and the three rings connected to the methine C atom are arranged in a propeller-like conformation. The heterocycle is linked to the solvent mol-ecule by an O-H⋯N hydrogen bond.

Journal: :European journal of medicinal chemistry 2021

The quinazolinone nucleus represents, among the class of fused heterocycles, a very important scaffold to obtain molecules with biological activities. A review literature revealed how such kind coming from natural or synthetic source, are associated wide range This is mainly directed towards 4-(3H)-quinazolinones N-3 substituted five membered heterocycle in which all possible combinations nitro...

Journal: :European Journal of Organic Chemistry 2021

The 2-pyrone moiety can be found in a large number of natural products with wide range biological activities, including antibiotic, antifungal, cytotoxic, neurotoxic, phytotoxic, anti-inflammatory and cardiotonic effects. With its heterocyclic structure encompassing the chemical nature conjugated dienes, lactones, Michael acceptors arenes, it undergo great variety transformations such as cycloa...

2016
Marina Uzelac Alan R Kennedy Eva Hevia Robert E Mulvey

This study establishes a new trans-metal-trapping (TMT) procedure based on a mixture of LiTMP (the base) and tris(trimethylsilylmethyl)gallium [Ga(CH2 SiMe3 )3 , GaR3 ] (the trap) that, operating in a tandem manner, is effective for the regioselective deprotonation of sensitive diazines in hydrocarbon solution, as illustrated through reactions of pyrazine, pyridazine, and pyrimidine, as well as...

Journal: :Chemical communications 2013
Qian Shao Jiean Chen Meihua Tu David W Piotrowski Yong Huang

An enantioselective organocatalytic process for the one-step synthesis of poly-substituted 1,2,4-triazolines is reported. The heterocycle formation is believed to go through a step-wise mechanism of nucleophilic addition of an azlactone to an azodicarboxylate in the presence of an organic base catalyst, followed by a TMSCHN2 mediated heterocyclization. Both theoretical calculations and experime...

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