Results 51 to 60 of about 14,956 (188)

A General, Enantioselective Synthesis of Protected Morpholines and Piperazines

, 2016
A short, high yielding protocol has been developed for the enantioselective and general synthesis of C2-functionalized, benzyl protected morpholines and orthogonally N,N′-protected piperazines from a common ...
Matthew C. O’Reilly (1368825), Craig W. Lindsley (203380)   +1 more
core   +1 more source

Synthesis of 2,6-Disubstituted Piperazines by a Diastereoselective Palladium-Catalyzed Hydroamination Reaction

, 2016
A highly diastereoselective intramolecular hydroamination is the key step in a modular synthesis of 2,6-disubstituted piperazines. The requisite hydroamination substrates were prepared in excellent yields by nucleophilic displacement of cyclic ...
Forrest E. Michael (1872319), Brian M. Cochran (2411149)   +1 more
core   +2 more sources

Investigation of piperazines as human carbonic anhydrase I, II, IV and VII activators

Journal of Enzyme Inhibition and Medicinal Chemistry, 2018
Four human (h) carbonic anhydrase isoforms (CA, EC 4.2.1.1), hCA I, II, IV, and VII, were investigated for their activation profile with piperazines belonging to various classes, such as N-aryl-, N-alkyl-, N-acyl-piperazines as well as 2,4-disubstituted ...
Andrea Angeli, Niccolò Chiaramonte, Dina Manetti, Maria Novella Romanelli, Claudiu T. Supuran   +4 more
doaj   +1 more source

Synthesis of Enantiopure Piperazines via Asymmetric Lithiation–Trapping of N‑Boc Piperazines: Unexpected Role of the Electrophile and Distal N‑Substituent

, 2016
A new method for the synthesis of enantiopure α-substituted piperazines via direct functionalization of the intact piperazine ring is described. The approach utilizes the asymmetric lithiation–substitution of an α-methylbenzyl-functionalized N-Boc ...
James D. Firth (1429162), Peter O’Brien (1429168), Leigh Ferris (1429165)   +2 more
core   +1 more source

Complete regioselective addition of grignard reagents to pyrazine N-oxides, toward an efficient enantioselective synthesis of substituted piperazines

, 2010
A conceptually new one-pot strategy for the synthesis of protected substituted piperazines via the addition of Grignard reagents to pyrazine N-oxides is presented. This strategy is high yielding (33-91% over three steps), step-efficient, and fast.
Andersson, Hans, Olsson, Roger,, Almqvist, Fredrik, Gustafsson, Magnus,, Das, Sajal, Banchelin, Thomas Sainte-Luce   +5 more
core   +1 more source

Iridium-Catalyzed Asymmetric Ring-Opening of Oxabenzonorbornadienes with N-Substituted Piperazine Nucleophiles

Molecules, 2015
Iridium-catalyzed asymmetric ring-opening of oxabenzonorbornadienes with N-substituted piperazines was described. The reaction afforded the corresponding ring-opening products in high yields and moderate enantioselectivities in the presence of 2.5 mol % [
Wen Yang, Renshi Luo, Dingqiao Yang
doaj   +1 more source

Simplified Procedure for General Synthesis of Monosubstituted Piperazines—From a Batch Reaction Vessel to a Flow (Microwave) Reactor

Molecules, 2020
We reported a novel simplified synthetic procedure for the preparation of monosubstituted piperazine derivatives which can now be easily prepared in a one-pot-one-step way from a protonated piperazine with no need of introduction of a protecting group ...
Dana Němečková, Eva Havránková, Jan Šimbera, Richard Ševčík, Pavel Pazdera   +4 more
doaj   +1 more source

Sorption and permeation of aqueous alkyl piperazines through hydrophilic and organophilic membranes: a transport analysis

, 1998
A detailed analysis of separation of N-methyl piperazine (NMP), N-ethyl pipera-zine (NEP), and water was undertaken by the pervaporation technique.
Pangarkar, V. G., Dagaonkar, M. V., Joshi, J. B., Sawant, S. B.   +3 more
core   +1 more source

Structure activity refinement of phenylsulfonyl piperazines as antimalarials that block erythrocytic invasion

, 2021
Structure activity refinement of phenylsulfonyl piperazines as antimalarials that block erythrocytic ...
Tania De Koning-Ward (13096974), HJ Sabroux (14461746), PR Gilson (9074540), W Nguyen (13462635), MG Dans (14461737), KN Lowes (14461743), BE Sleebs (14461755), VM Avery (14461749), S Duffy (7707776), DW Wilson (14461752), A Ngo (9854420), O Romeo (13410972), MR Gancheva (14461740)   +12 more
core  

Opportunities and challenges for direct C–H functionalization of piperazines

Beilstein Journal of Organic Chemistry, 2016
Piperazine ranks within the top three most utilized N-heterocyclic moieties in FDA-approved small-molecule pharmaceuticals. Herein we summarize the current synthetic methods available to perform C–H functionalization on piperazines in order to lend ...
Zhishi Ye, Kristen E. Gettys, Mingji Dai
doaj   +1 more source