155156-87-9Relevant articles and documents
Efficient organocatalyst supported on a simple ionic liquid as a recoverable system for the asymmetric diels-alder reaction in the presence of water
De Nino, Antonio,Maiuolo, Loredana,Merino, Pedro,Nardi, Monica,Procopio, Antonio,Roca-Lpez, David,Russo, Beatrice,Algieri, Vincenzo
, p. 830 - 835 (2015)
The synthesis, characterization, and evaluation of a new highly efficient organocatalyst, namely, (5S)-2,2,3-trimethyl-5-thiobenzylmethyl-4-imidazolidinone hydrochloride, has been achieved. The catalyst possesses important structural features that should increase the catalytic efficiency and solubility in polar media. The application of the ionic-liquid-supported imidazolidinone catalyst in enantioselective Diels-Alder reactions was investigated. The Diels-Alder reactions of several dienes and dienophiles proceeded efficiently in the presence of the catalyst to provide the desired products in moderate to good yields and from good to excellent enantioselectivities. The conformation study confirms that in the transition state the Re face is shielded completely by the phenyl ring and an approach on the less hindered Si face is preferred. Particularly remarkable is the fact that the entire ionic liquid/HCl 0.01 M/catalyst system can be recovered and reused in up to six runs without an appreciable loss of catalytic activity. Confirming the conformation: The synthesis, characterization, and evaluation of a new highly efficient imidazolidinone organocatalyst is achieved. The catalyst is investigated in enantioselective Diels-Alder reactions, and a conformation study confirms the approach on the less hindered Si face. [mPy][OTf]=Methylpyridinium triflate.
Synthesis of Main-Chain Ionic Polymers of Chiral Imidazolidinone Organocatalysts and Their Application to Asymmetric Diels–Alder Reactions
Haraguchi, Naoki,Takenaka, Nagisa,Najwa, Aisyah,Takahara, Yuta,Mun, Mah Kar,Itsuno, Shinichi
, p. 112 - 123 (2017/12/26)
Main-chain ionic polymers incorporating chiral imidazolidinone moieties in the polymer main chain were successfully synthesized by the polyaddition reaction of a chiral imidazolidinone dimer with a disulfonic acid. The organocatalytic activities of these polymers were investigated in the asymmetric Diels–Alder reaction between trans-cinnamaldehyde and 1,3-cyclopentadiene. The catalytic performance of the polymers was found to be sensitive to the chemical structure of the disulfonate units and the imidazolidinone dimer. With the use of these heterogeneous polymeric chiral organocatalysts, enantioselectivities of up to 99% for the endo isomer were obtained. This result was higher than those obtained with corresponding monomeric and dimeric counterparts in a homogeneous solution. The polymeric chiral organocatalyst was recovered and reused several times, maintaining its high enantioselectivity. (Figure presented.).
Highly enantioselective diels-alder reaction catalyzed by chiral imidazolidinone
Wang, Yongjiang,Xu, Xiaoliang,Pei, Wen
experimental part, p. 2032 - 2041 (2009/11/30)
New chiral imidazolidinone with an indole group was synthesized and used to catalyze the Diels-Alder reaction of α,β-unsaturated aldehyde with diene. High enantiomeric excesses and good yields were obtained. The reaction media were also surveyed. The best
