155156-86-8Relevant academic research and scientific papers
Flow Chemistry-Enabled Divergent and Enantioselective Total Syntheses of Massarinolin A, Purpurolides B, D, E, 2,3-Deoxypurpurolide C, and Structural Revision of Massarinolin A
Cui, Chengsen,Dai, Mingji,Wang, Ye-Cheng
, p. 24828 - 24832 (2021)
Massarinolin A and purpurolides are bioactive bergamotane sesquiterpenes condensed with a variety of synthetically challenging ring systems: a bicyclo[3.1.1]heptane, an oxaspiro[3.4]octane, and a dioxaspiro[4.4]nonane (oxaspirolactone). Herein, we report the first enantioselective total syntheses of massarinolin A, purpurolides B, D, E, and 2,3-deoxypurpurolide C. Our synthesis and computational analysis also led to a structural revision of massarinolin A. The divergent approach features an enantioselective organocatalyzed Diels–Alder reaction to install the first stereogenic center in high ee, a scalable flow photochemical Wolff rearrangement to build the key bicyclo[3.1.1]heptane, a furan oxidative cyclization to form the oxaspirolactone, a late-stage allylic C?H oxidation, and a Myers’ NBSH-promoted sigmatropic elimination to install the exo methylene group of massarinolin A.
Reusable montmorillonite-entrapped organocatalyst for asymmetric Diels-Alder reaction
Mitsudome, Takato,Nose, Kenta,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
, p. 5464 - 5466 (2008)
A chiral organocatalyst was successfully entrapped by montmorillonite clay using the cation-exchange method. The mont-entrapped organocatalyst acted as a highly efficient and reusable heterogeneous catalyst for the asymmetric Diels-Alder reaction, without loss of its initial activity.
Highly enantioselective diels-alder reaction catalyzed by chiral imidazolidinone
Wang, Yongjiang,Xu, Xiaoliang,Pei, Wen
, p. 2032 - 2041 (2009)
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
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.).
Asymmetric diels-alder reactions of α,β-unsaturated aldehydes catalyzed by a diarylprolinol silyl ether salt in the presence of water
Hayashi, Yujiro,Samanta, Sampak,Gotoh, Hiroaki,Ishikawa, Hayato
supporting information; experimental part, p. 6634 - 6637 (2009/03/12)
(Chemical Equation Presented) Water, water, everywhere: The title reaction predominantly affords the exo isomer with excellent enantioselectivity (see scheme; TMS=trimethylsilyl). The synthesis can be carried out without organic solvents and provides the products by distillation. Water increases the rate and enantioselectivity of the reaction.
A recyclable fluorous organocatalyst for Diels-Alder reactions
Chu, Qianli,Zhang, Wei,Curran, Dennis P.
, p. 9287 - 9290 (2007/10/03)
Chiral fluorous imidazolidinone catalyst 2 provides consistently high enantioselectivities in Diels-Alder reactions of dienes and α,β-unsaturated aldehydes. The catalyst can be readily separated from the reaction products by fluorous solid-phase extractio
Asymmetric Organocatalytic Diels-Alder Reactions on Solid Support
Selkaelae, Sami A.,Tois, Jan,Pihko, Petri M.,Koskinen, Ari M. P.
, p. 941 - 945 (2007/10/03)
Asymmetric organocatalysis on solid support combines the environmental advantages of metal-free catalysts and the ease of operation of solid-supported reagents. Enantioselective organo-catalytic Diels-Alder reactions have been demonstrated by two differen
