62811-39-6Relevant academic research and scientific papers
Enantioselective Conjugate Additions of 2-Alkoxycarbonyl-3(2 H)-furanones
Vojá?ková, Petra,Chalupa, David,Prieboj, Jozef,Ne?as, Marek,?venda, Jakub
supporting information, p. 7085 - 7089 (2018/11/23)
Enantioselective conjugate additions of in situ generated 2-alkoxycarbonyl-3(2H)-furanones to three distinct types of π-electrophiles (terminal alkynones, α-bromo enones, and α-benzyl nitroalkenes) are reported. Catalysis by a nickel(II)-diamine complex provided alkynone-derived adducts with high enantioselectivity, preferentially as the Z-isomers, and completely suppressed the undesired O-alkylation pathway. A cupreidine-based catalyst enabled extension of the enantioselective conjugate additions to α-bromo enones and α-benzyl nitroalkenes. The densely functionalized adducts that result are useful precursors to synthetic analogs of spirocyclic natural products pseurotins.
Construction of chiral 2-substituted octahydroindoles from cyclic ketones and nitroolefins bearing only one α-substituent
Han, Yong,Zheng, Bo,Peng, Yungui
, p. 1136 - 1142 (2015/04/22)
A dual catalytic system has been developed following the screening of a series of chiral primary amine catalysts and chiral phosphoric acid catalysts for the Michael addition of cyclic ketones to nitroolefins bearing only one α-substituent. The resulting γ-nitro ketones, which contain a substituent on the carbon connected to the nitro group, were formed in excellent yields (>80%) with high levels of stereoselectivity (up to 94:6 dr and 98% ee) when the reaction was performed in benzene at 0 °C with 10 mol% of the optimal amine/phosphoric acid combination (1:1) as a catalyst. Subsequent reduction of the nitro group followed by intramolecular reductive amination could afford optically active cis-octahydroindole analogues bearing a non-functional substituent at their 2-position.
A novel method to access chiral nonnatural 2,4-disubstituted pyrrolidines from aldehydes and nitroolefins only with an α-substituent
Zheng, Bo,Wang, Hui,Han, Yong,Liu, Changlu,Peng, Yungui
, p. 4561 - 4563 (2013/06/04)
A series of α-substituted nitroolefins were employed in organocatalytic asymmetric Michael reactions with aldehydes. γ-Nitro carbonyl products were achieved in good yields (up to 86%) with good stereoselectivities (up to 96% ee and 24 : 1 dr). Reduction of the nitro group followed by intramolecular reductive amination successfully afforded various novel optically active 2,4-disubstituted pyrrolidine compounds.
Novel synthesis of α-nitroalkenes from nitroalkanes via halogenation of intermediate N,N-bis(silyloxy)enamines
Kunetsky, Roman A.,Dilman, Alexander D.,Struchkova, Marina I.,Tartakovsky, Vladimir A.,Ioffe, Sema L.
, p. 5203 - 5205 (2007/10/03)
An approach to conjugated nitroalkenes via oxidation of N,N-bis(silyloxy)enamines with bromine or iodine in the presence of tetra-n-butylammonium acetate is described. The acetate ion plays a key role by acting as a mild desilylating reagent. This new strategy allows the synthesis of α-nitroalkenes from the corresponding nitroalkanes.
32. 2'-Nitro-2'-propen-1'-yl 2,2-Dimethylpropanoate (NPP), A Multiple Coupling Reagent
Seebach, Dieter,Knocherl, Paul
, p. 261 - 283 (2007/10/02)
The title compound 1 (NPP) is prepared from formaldehyde, nitromethane, and pivaloyl chloride.It is shown to be a versatile nitroallylating reagent combining with nucleophiles as different as anilines, indoles, enolates, and organolithium compounds.This i
NITROALLYLATION OF HIGHLY REACTIVE ORGANOLITHIUM COMPOUNDS BY 2-NITRO-3-PIVALOYLOXI-1-PROPENE (NPP)
Knochel, Paul,Seebach, Dieter
, p. 3223 - 3226 (2007/10/02)
The nitroolefin 1 (NPP) efficiently transfers a 2-nitroallyl group even to the most reactive nucleophilic centres of organolithium reagents to give the products of type 2 listed in the table.
