نتایج جستجو برای: ring opening

تعداد نتایج: 167807  

Journal: :The Journal of organic chemistry 2009
Chang-Feng Li Wen-Jing Xiao Howard Alper

Palladium-catalyzed ring-opening thiocarbonylation of vinylcyclopropanes (VCPs) with thiols and carbon monoxide affords the corresponding unsaturated thioesters in moderate to excellent yields. This reaction provides a general method for the ring-opening thiocarbonylation of VCPs. It further demonstrates the utility of transition metal catalysts for the synthesis of organosulfur compounds.

Journal: :Chemical communications 2009
Sae Young Yun Saron Catak Won Koo Lee Matthias D'hooghe Norbert De Kimpe Veronique Van Speybroeck Michel Waroquier Yongeun Kim Hyun-Joon Ha

The ring opening of 2-substituted N,N-dibenzylaziridinium ions by bromide exclusively occurs at the substituted aziridine carbon atom in a stereospecific way, whereas the opposite regioselectivity was observed for hydride-induced ring opening at the unsubstituted position; furthermore, this unprecedented hydride-promoted reactivity was validated by means of Density Functional Theory (DFT) calcu...

Journal: :Chemical communications 2012
Hans S Smalø Einar Uggerud

Density functional theory calculations show that both ring opening and chain dissociation of polymeric triazoles are facilitated by mechanical stretching of the molecules--the latter more than the former. Experimentally observed ring opening upon sonication can therefore not be explained by a mechanical stretching mechanism alone.

Journal: :Chemical communications 2014
Jun Li Yuting Liao Yulong Zhang Xiaohua Liu Lili Lin Xiaoming Feng

The asymmetric ring-opening of meso-aziridines with primary alcohols is realized using an N,N'-dioxide-Mg(OTf)2 complex as the catalyst. The desired vicinal trans-β-amino ethers are afforded in good yields and enantioselectivities. Aniline and water could also be used as the nucleophiles for the ring-opening in an identical catalyst system.

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی برق و کامپیوتر 1391

this thesis is presented 10 ghz voltage controlled ring oscillator for high speed application. the voltage controlled ring oscillator was designed and fabricated in 0.13یm cmos technology. the oscillator is 7-stages ring oscillator with one inverter replaced by nand-gate for shutting down in the ring oscillator during idle mode. tri-state inverter was used to control of 126 bit vector in ri...

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