نتایج جستجو برای: diastereoselectivity

تعداد نتایج: 565  

Journal: :Chemical communications 2010
Tatsuya Shiozawa Mohammed K Hossain Takashi Ubukata Yasushi Yokoyama

A bisthienylethene with hitherto unprecedented facial chirality imposed by a triethyleneglycol bridge on a thiophene ring was synthesized and its photochromic ring closure was shown to occur with 100% diastereoselectivity upon UV-light irradiation.

Journal: :Angewandte Chemie 2012
Xiao Shen Wei Zhang Lei Zhang Tao Luo Xiaolong Wan Yucheng Gu Jinbo Hu

Chiral transfer: the fluorinated sulfoximine (see scheme; Ts=p-toluenesulfonyl) was synthesized and used as the first chiral fluoromethylenation reagent for the synthesis of cyclopropanes that contain fluorinated tertiary stereogenic carbon centers in good yields, good diastereoselectivity, and excellent enantioselectivity.

Journal: :Chemical communications 2011
Jun Xuan Ying Cheng Jing An Liang-Qiu Lu Xiao-Xiao Zhang Wen-Jing Xiao

A new and efficient synthesis of highly substituted tetrahydroimidazole derivatives by means of visible light-induced intramolecular cyclization reactions has been described. This photoredox catalytic reaction exhibited high diastereoselectivity and afforded the desired products in good yields.

Journal: :Organic & biomolecular chemistry 2013
Jonathan Day Maliha Uroos Richard A Castledine William Lewis Ben McKeever-Abbas James Dowden

Cycloaddition reactions between pyridinium ylides and 3-alkenyl oxindoles that proceed in high yield and with very good regio- and diastereoselectivity are reported. The resulting cycloadducts have the same stereochemistry of biologically active oxindole alkaloids, such as strychnofoline.

Journal: :Chemical communications 2005
Hideaki Saito J Sivaguru Steffen Jockusch Yoshihisa Inoue Waldemar Adam Nicholas J Turro

Oxazolidinone-functionalized enecarbamates undergo diastereoselective E/Z photoisomerization upon direct and triplet sensitized irradiations with chiral/achiral sensitizers, showing that the enhanced product diastereoselectivity depends on the solvent and temperature.

Journal: :European Journal of Organic Chemistry 2021

An efficient method for the synthesis of (S)-7-aza-tryptophan via tridentate chiral auxiliary derived Ni(II)-complexes has been developed. This three-step includes alkylation, disassembling and Fmoc-protection. The desired Fmoc-L-7-AzaTrp-OH was obtained in over 49 % yield with excellent diastereoselectivity.

Journal: :Chemical communications 2010
Gaurav Bhargava Beatriz Trillo Marisel Araya Fernando López Luis Castedo José L Mascareñas

We report a Pd-catalyzed intramolecular [3C + 2C + 2C] cycloaddition between alkylidenecyclopropanes, alkynes and alkenes. The method provides synthetically relevant 5-7-5 tricyclic structures, with good chemoselectivity and complete diastereoselectivity.

Journal: :Chemical communications 2004
Pauline Chiu Sze Kar Leung

Conjugate reduction of alkynones by stoichiometric [(Ph(3)P)CuH](6) or catalytic [(Ph(3)P)CuH](6) and polymethyl-hydrosiloxane proceeds to cyclization by an aldol reaction with tethered ketones to generate [small beta]-hydroxyenones with good diastereoselectivity.

Journal: :Chemical communications 2008
Kévin M Joly Claire Wilson Alexander J Blake James H R Tucker Christopher J Moody

Planar chirality associated with the ferrocene in ferrocenyl oximes and hydrazones bearing chiral auxiliaries effectively competes with or overrides the normally excellent stereocontrol afforded by the auxiliary in determining the diastereoselectivity of addition to the C=N bond.

Journal: :Chemical communications 2011
Palash Pandit Nirbhik Chatterjee Dilip K Maiti

Intramolecular formal 1,3-dipolar cycloaddition of ketoimine is developed with PhIO for the first synthesis of fused-Δ(1)-pyrrolines. The scope of the reaction, complete diastereoselectivity and its rationalization by a computational study are reported.

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید