References
References Cited By Our Paper
Shabashov, D.; Daugulis, O. J. Am. Chem. Soc. 2010, 132, 3965-3972.
Zaitsev, V. G.; Shabashov, D.; Daugulis, O. J. Am. Chem. Soc. 2005, 127, 13154-13155.
More on Paper by Zaitsev, et al. :
The method proposed to transform molecule 18 to molecule 19 presents a new method for cleaving the amide directing group while bypassing the need for extreme pH or heat changes. Being able to keep a mild experimental environment allows further reaction possibilities with the Daugulis methodology for synthesis. A common problem in chemical reactions is the use of transition metal complexes that are able of selective, catalytic functionalization of C-H bonds. However, the Daugulis methodology is an arylation process based on C-H activation that allows for the β-arylation of carboxylic acid derivatives and γ-arylation of amine derivatives. Though the exact mechanism for these reactions is still under investigation, the Daugulis methodology successfully transformed 8-aminoquinoline, a compound chosen for its lack of activated benzylic C-H bonds, into arylated amides. This novel method of β-arylation of carboxylic amides possessing a directing aminoquinoline group is mild and highly regioselective.
Papers that have cited Zaitsev, et al.:
Morimoto, H.; Fujiwara, R.; Shimizu, Y.; Morisaki, K.; Ohshima, T. Org. Lett. 2014, 16, 2018-2021.
For the purpose of the study, a method of stereoselectively altering a compound under extremely mild conditions with palladium metal was needed. The Daugulis methodology of acylation, as founded by Zaitsec, et al., provided a model with such conditions.
They devised a high-yield amidation of esters using small amounts of palladium catalyst under mild conditions. This amidation can be used to form the amide reactant (molecule 18) that undergoes our reaction to form molecule 19.
Gutekunst, W. R.; Baran, P. S. J. Org. Chem. 2014, 79, 2430-2452.
Gutekunst and Baran needed a directing group for their compound that could more easily deprotected. Zaitsec, et al. had concluded that picolinamide was a decent directing group in their report. Therefore, Gutekunst and Baran resolved to use a picolinamide-based compound for a directing group.
In their study with piperarborenines, they discovered a reductive conversion of 8-aminoquinoline amide directing group to an aldehyde under mild conditions. This conversion is similar in its reactant and product to our reaction but employs a different mechanistic method of converting an amide to an aldehyde.
Franzoni, I.; Mazet, C. Org. Biomol. Chem. 2014, 12, 233-241.
Ivan Franzoni and Clément Mazet got their inspiration from this paper from the ability to create the Pd-catalyzed direct C-H arylation of remote aliphatic positions. Franzoni and Mazet used this information in order to find more milder conditions and more general methods in order to complete the remote functionalization of γ C(sp3)–H bonds (5 mol% Pd(OAc)2, 1.5 equiv. aryliodide, 1.0 equiv. Ag2CO3, 80°C).
They studied selectively functionalizing carbonyl derivatives at distant positions using palladium catalyst. This new use of palladium catalyst in reactions of carbonyl derivatives is grounded on the study by Zaitsev, which was inspired by our paper.