6328-22-9Relevant articles and documents
Development of a Kilogram-Scale Process for the Enantioselective Synthesis of 3-Isopropenyl-cyclohexan-1-one via Rh/DTBM-SEGPHOS-Catalyzed Asymmetric Hayashi Addition Enabled by 1,3-Diol Additives
Simmons, Eric M.,Mudryk, Boguslaw,Lee, Andrew G.,Qiu, Yuping,Razler, Thomas M.,Hsiao, Yi
, p. 1659 - 1667 (2017/10/25)
The development of a scalable process for the Rh-catalyzed asymmetric 1,4-addition of (isopropenyl)pinacolboronate to 2-cyclohexen-1-one is reported. High-throughput ligand screening and initial optimization studies identified DTBM-SEGPHOS as an effective ligand along with a heptane/MeOH mixed solvent system. An inhibitory effect of the pinacol byproduct was identified, which could be mitigated by the addition of a 1,3-diol such as neopentyl glycol (npg). This process was demonstrated on 1 kg scale with 0.6 mol % Rh, producing (S)-1 in 82% yield and 99.6% ee, and was successfully scaled up at a vendor on 100 kg scale.
The cinchona primary amine-catalyzed asymmetric epoxidation and hydroperoxidation of α,β-unsaturated carbonyl compounds with hydrogen peroxide
Lifchits, Olga,Mahlau, Manuel,Reisinger, Corinna M.,Lee, Anna,Fares, Christophe,Polyak, Iakov,Gopakumar, Gopinadhanpillai,Thiel, Walter,List, Benjamin
supporting information, p. 6677 - 6693 (2013/06/05)
Using cinchona alkaloid-derived primary amines as catalysts and aqueous hydrogen peroxide as the oxidant, we have developed highly enantioselective Weitz-Scheffer-type epoxidation and hydroperoxidation reactions of α,β-unsaturated carbonyl compounds (up to 99.5:0.5 er). In this article, we present our full studies on this family of reactions, employing acyclic enones, 5-15-membered cyclic enones, and α-branched enals as substrates. In addition to an expanded scope, synthetic applications of the products are presented. We also report detailed mechanistic investigations of the catalytic intermediates, structure-activity relationships of the cinchona amine catalyst, and rationalization of the absolute stereoselectivity by NMR spectroscopic studies and DFT calculations.
Pt-catalyzed oxidative rearrangement of cyclic tertiary allylic alcohols to enones using aqueous hydrogen peroxide
Nagamine, Takashi,Kon, Yoshihiro,Sato, Kazuhiko
supporting information; experimental part, p. 744 - 746 (2012/09/22)
An oxidative rearrangement of cyclic tertiary allylic alcohols to β-disubstituted α,β-unsaturated ketones by Pt black catalyst with aqueous hydrogen peroxide is described. The reaction proceeds under organic solvent- and halide-free conditions and gives only water as a coproduct. The Pt black catalyst is commercially available and can be reused at least four times.
