120290-01-9Relevant academic research and scientific papers
Michael addition at neutral pH: A facile synthesis of 1,3-dinitroalkanes
Bora, Porag,Bora, Pranjal P.,Wahlang, Barisha,Bez, Ghanashyam
, p. 1261 - 1266 (2017)
Base-catalyzed Michael addition of nitroalkane to conjugated nitroalkene suffers serious practical difficulties due to the formation of oligomeric byproduct. Given its importance for synthesis of pharmacologically relevant organic compounds, a scalable synthesis of 1,3-dinitroalkane is developed by addition of nitroalkane to nitroalkene in aqueous phosphate buffer at pH 7.0 with no added traditional base catalyst.
Highly enantioselective direct Michael addition of nitroalkanes to nitroolefins catalyzed by La(OTf)3/N,N′-dioxide complexes
Yang, Xu,Zhou, Xin,Lin, Lili,Chang, Lu,Liu, Xiaohua,Feng, Xiaoming
, p. 7079 - 7081 (2008)
(Chemical Equation Presented) It all adds up: A chiral La(OTf) 3/N,N′-dioxide complex has been developed for the asymmetric direct Michael addition of nitroalkanes to nitroalkenes. This reaction afford 1,3-dinitro compounds with two stereocenters in good yields with high diastereo- and enantioselectivity (up to d.r. 93:3, 97% ee; see scheme, Tf=trifluoromethanesulfonyl) under mild conditions.
A concerted two-prong approach to the: In situ allosteric regulation of bifunctional catalysis
McGuirk, C. Michael,Mendez-Arroyo, Jose,D'Aquino, Andrea I.,Stern, Charlotte L.,Liu, Yuan,Mirkin, Chad A.
, p. 6674 - 6683 (2016)
Herein, we report the reversible in situ on-off allosteric regulation of hydrogen-bond-donating (HBD)-Lewis base co-catalytic activity via a concerted two-prong methodology entailing cooperative acid-base chemistry and a structurally addressable coordination complex. Specifically, a heteroligated Pt(ii) weak-link approach (WLA) tweezer complex containing both a hemilabile squaramide-piperidine-based catalytic ligand and a sodium sulfonate hydrogen-bond-accepting (HBA) ligand was synthesized. Due to the hemilabile nature of the catalyst-containing ligand, the heteroligated complex can be reversibly toggled in situ between a flexible, semi-open state and a rigid, fully closed state upon the addition of elemental ion cues. 1H NMR spectroscopy titration studies show that in the semi-open state interligand hydrogen-bonding prevents substrate recognition by the squaramide unit, while in the fully closed state ligand-ligand interactions are prevented. This results in a catalytically active closed state, whereas in the semi-open state, when the piperidine tertiary amine is deliberately protonated, no catalytic activity is observed. Reversible interconversion between the active fully closed state and the dormant protonated semi-open state is achieved in the presence of substrate upon the concerted addition and abstraction of both a proton and a coordinating elemental anion. In this work, allosteric regulation of catalytic activity is demonstrated for both the Michael addition of nitroethane to β-nitrostyrene and the ring-opening of l-(-)-lactide. Taken together, this work details a potentially generalizable platform for the on-off allosteric regulation of a family of HBD-Lewis base co-catalysts capable of catalyzing a broad scope of reactions, including the living ring-opening polymerization of cyclic esters.
Chiral squaramide-catalyzed highly diastereo- and enantioselective direct Michael addition of nitroalkanes to nitroalkenes
Yang, Wen,Du, Da-Ming
supporting information; experimental part, p. 12706 - 12708 (2012/01/06)
An efficient highly diastereo- and enantioselective direct Michael addition of nitroalkanes to nitroalkenes catalyzed by chiral squaramide catalyst has been developed. This organocatalytic reaction with a low catalyst loading (2 mol%) proceeded well to af
