Palladium-Catalyzed (<i>Z</i>)-Selective Allylation of Nitroalkanes: Access to Highly Functionalized Homoallylic Scaffolds
作者:Àlex Cristòfol、Eduardo C. Escudero-Adán、Arjan W. Kleij
DOI:10.1021/acs.joc.8b01372
日期:2018.9.7
presence of vinyl-substituted cyclic carbonates, providing a wide variety of functionalized homoallylated compounds with exquisite stereocontrol. This Pd-mediated procedure features operational simplicity, versatile substrate combinations, and also allows for the sequential introduction of different allyl groups in the nitroalkane scaffolds with high levels of stereocontrol through the intermediacy of a (Z)-configured
The nitroethylation of amiens is demonstrated to be a general reaction for bases in the pKa range of 2 – 8 and that it proceeds through a key intra-molecular quenching step. The reaction, illustrated with aromaticamines, aliphatic amines and heterocyclic bases, offers attractive routes to diverse heterocyclic systems.
1. Als beste Laboratoriumsmethode für die Herstellung von Nitroäthylen (Gesamtausbeute von 43% d. Th., bezogen auf Formaldehyd) wurde die thermische Spaltung des Nitroäthanolpropionats ausgearbeitet.
Synthesis of Some 2-Aminonitroethanes via Silica Gel-Catalyzed Nitro-Mannich Reaction
作者:Ali S. Mahasneh
DOI:10.1515/znb-2006-0918
日期:2006.9.1
Abstract A direct one pot, three-component nitro-Mannich reaction of a nonenolizable aldehyde, aniline or one of its ring-substituted derivatives and nitromethane was carried out on silica gel surface. The products of the reaction, 2-aminonitroethane, were obtained in high yields. IR, 1H NMR, 13C NMR spectra and elemental analysis confirmed the structures of the products.
An organocatalytic enantioselective formal C(sp(2))-H alkylation is reported. This alkylative desymmetrization of prochiral 2,2-disubstituted cyclopentene-1,3-dione is catalyzed by a bifunctional tertiary aminourea derivative, utilizes air-stable and inexpensive nitroalkanes as the alkylating agents, and delivers synthetically versatile five-membered carbocycles containing an all-carbon quaternary stereogenic center remote from the reaction site in excellent enantioselectivity.