Main Reference: D.; Harada, S.; Nishida, A. J. Am. Chem. Soc. 2008, 130, 12588-12589.
The Main Reference paper discusses the reactivity and selectivity of 1-Methoxy-3-trimethylsiloxy- 1,3-butadiene (Danishefsky’s diene) in the Diels-Alder reaction with different catalysts and electron deficient Alkenes.
The paper studies in class titled Synthesis of Potent Antimalarial Amphiletene, says that they have discovered a chemoselective inversion of tertiary alcohols with TMSCN, which in combination with the research reported in this paper will lead to the synthesis of amphilectene and isocyanoterpene analogs for the treatment of Malaria.
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Sakakura, A.; Kondo, R.; Matsumura, Y.; Akakura, M.; Ishihara, K. J. Am. Chem. Soc. 2009, 131, 17762-17764.
This paper builds upon the research reported in the reference article. The first sentence in the introduction of this paper cites our reference paper. It says, “Although numerous chiral Lewis acid catalysts have been reported for the asymmetric Diels-Alder reaction, there are still some drawbacks with regard to catalytic activity, enantioselectivity, and the range of substrates”.
Akira Sakakura and his colleagues acknowledge that Lewis acid catalysts can be utilized to initiate the asymmetric Diels-Alder reaction. However, this team states that this reaction is imperfect and builds upon the research by designing a chiral cationic catalyst using weak secondary interaction in order to stabilize the cationic species to produce a more homogenous enantioselective product.
Li, M.; Carreras, V.; Jalba, A.; Ollevier, T. Org. Lett. 2018, 20, 995-998.
This article begins by discussing the importance of the Diels-Alder reaction and the research conducted by Narasaka, Corey, Evans, Bolm, Sudo and colleges who used oxazolidinone derivatives as substrates to perform an asymmetric Diels-Alder reaction. Knowing Lewis acid catalysis could improve the stereocontrol of the Diels-Alder reaction, different metals, catalyst loadings and temperatures were screened to improve the efficiency of the reaction.
In the end the researchers were able to discover, “an efficient catalytic system capable of catalyzing the Diels–Alder reaction between various dienophiles and dienes to give high isolated yields (up to 99%) with high ee’s (up to 98%) of the desired products”.
Liu, Z.; Lin, X.; Yang, N.; Su, Z.; Hu, C.; Xiao, P.; He, Y.; Song, Z. J. Am. Chem. Soc. 2016, 138, 1877-1883.
The endo-Diels-Alder product is generally favored due to the stability in the endo transition state which leads to its rapid formation. This article studies the unique steric effect of germinal bis(silane) which leads to the exo-selective intermolecular Diels-Alder reaction with α,β-unsaturated carbonyl compounds. The paper cites the research discovered in the reference paper when it says, “It has been shown by the previous results that moderate exo/endo ratios were generally obtained under either Lewis acid-catalysis or organocataly-sis”.
While the exo/endo ratio reported in other papers under Lewis acid-catalysis or organocataly-sis was low, when Dr. Liu and his colleagues performed this reaction with Bis(silane) exo/endo ratios of (91:9 to 93:7) were achieved.
