نتایج جستجو برای: aldol reaction

تعداد نتایج: 413188  

Journal: :Chemical Science 2023

The six-pots synthesis of latanoprost has been accomplished with excellent diastereo- and enantioselectivities through an organocatalyst-mediated Michael reaction, a substrate-controlled intramolecular Mukaiyama aldol reaction as key steps.

Journal: :Chemical communications 2012
Taichi Kano Sunhwa Song Keiji Maruoka

A diastereo- and enantioselective aldol reaction between aldehydes and a synthetically useful ketomalonate 1c as a hydrated form was developed, and either anti- or syn-aldol adducts having a chiral tetrasubstituted carbon center were obtained in high enantioselectivities by use of a tetrazole analogue of L-proline (S)-2 or an axially chiral amino sulfonamide (S)-3 as catalyst.

Journal: :Chemical communications 2012
Thierry Ollevier Baptiste Plancq

A highly enantioselective method for the catalytic Mukaiyama aldol reaction of silyl enol ethers with aldehydes in aqueous conditions was developed. The desired aldol products were obtained in excellent yields, diastereo- and enantioselectivities. Structural evidence of the pre-catalyst revealed an unprecedented heptadentate Fe(II) complex with the chiral bipyridine ligand.

2016
Hui Dong Jie Liu Lifang Ma Liang Ouyang

A chitosan aerogel catalyzed asymmetric aldol reaction of ketones with isatins in the presence of water is described. This protocol was found to be environmentally benign, because it proceeds smoothly in water and the corresponding aldol products were obtained in excellent yields with good enantioselectivities.

Journal: :The Journal of organic chemistry 2015
Masaharu Sugiura Yasuhiko Ashikari Makoto Nakajima

TiCl4-promoted aldol reaction of ketones as aldol acceptors followed by elimination of the titanoxy group from the Ti-aldolates affords β,β-disubstituted α,β-unsaturated carbonyl compounds in a one-pot procedure. The use of additives, such as DMF, N,N,N',N'-tetramethylethylenediamine, and pyridine, in the elimination step was found to be important.

Journal: :Organic & biomolecular chemistry 2009
Shu-Ping Luo Zhao-Bo Li Li-Ping Wang Yi Guo Ai-Bao Xia Dan-Qian Xu

The asymmetric tandem oxa-Michael-aldol reaction of salicylic aldehyde derivatives with alpha,beta-unsaturated aldehydes catalyzed by a chiral amine/chiral acid organocatalytic system was investigated. The organocatalytic system of (S)-diphenylpyrrolinol trimethylsilyl ether with chiral shift reagent (S)-Mosher acid presented a synergistic effect in the improvement of reaction performance and o...

Journal: :Organic letters 2000
M E Jung R Marquez

[reaction: see text] The nonaldol aldol process developed in our laboratories has been applied to the synthesis of a C(1)-C(11) fragment 22 of the novel macrocyclic cytotoxic agents tedanolide and 13-deoxytedanolide 1 and 2. The commercially available hydroxy ester 7 was converted in 24 steps into compound 22 using two nonaldol aldol reactions.

Journal: :Chemical communications 2015
Taichi Kano Hiroki Maruyama Ryu Sakamoto Keiji Maruoka

In this communication, we present a regioselectivity switch for the chiral amine-catalysed asymmetric addition of aldehydes to reactive enals to afford either aldol adducts or conjugate adducts in a stereoselective fashion. The unprecedented asymmetric aldol reaction of aldehydes with enals was realized by the use of a diarylprolinol catalyst, giving synthetically useful and important chiral al...

Journal: :Molecules 2016
Marco Araújo Iván Muñoz Capdevila Santiago Díaz-Oltra Beatriu Escuder

A heterogeneous supramolecular catalytic system for multicomponent aldol-'click' reactions is reported. The copper(I) metallohydrogel functionalized with a phenyltriazole fragment was able to catalyze the multicomponent reaction between phenylacetylene, p-nitrobenzaldehyde, and an azide containing a ketone moiety, obtaining the corresponding aldol products in good yields. A possible mechanistic...

Journal: :Acta Chemica Scandinavica 1972

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید