116437-30-0Relevant articles and documents
Studies on the aza-Claisen rearrangement of 7 to 9-membered vinylazacycles
Kim, Seok-Ho,Lee, Won-Il,Kim, Seon-Mi,Jung, Jae-Kyung,Jang, Jaebong,Sim, Jaehoon,Jung, Jong-Wha,Suh, Young-Ger
, p. 886 - 899 (2016)
A systematic study on the amide enolate-induced aza-Claisen rearrangement (ACR) of 7 to 9-membered vinylazacycles has been carried out, resulting in an efficient synthetic method to prepare 11 to 13-membered macrolactams. Key feature includes introduction of electron-donating substituents at α-position of the amide substrates possessing 7 to 9-membered vinylazacycles to facilitate amide enolate-induced ACR. In addition, substituent effects on ACR has been discussed based on the experimental results. We believe this study would provide experimental evidences for the substituent effects and envision for the synthetic application of ACR-induced ring expansion.
Unexpected Rearrangement of N-Allyl-2-phenyl-4,5-Dihydrooxazole-4-Carboxamides to Construct Aza-Quaternary Carbon Centers
Choi, Goyeong,Jo, Seoyoung,Mun, Juyeon,Jeong, Yonguk,Kim, Seok-Ho,Jung, Jong-Wha
, (2019/12/25)
The unexpected rearrangement of N-allyl-2-phenyl-4,5-dihydrooxazole-4-carboxamides in the presence of LiHMDS has been found. The key features are: (1) the net reaction consisted of 1,3-migration of the N-allyl group, (2) the rearrangement produced a congested aza-quaternary carbon center, (3) both cyclic and acyclic substrates underwent the unexpected rearrangement to afford products in moderate to high yields, and (4) the reaction seemed to be highly stereoselective. In addition, a plausible mechanism has been discussed.
Organometallic Ring-Opening Reactions of N-Acyl and N-Alkoxycarbonyl Lactams. Synthesis of Cyclic Imines
Giovannini, Arianna,Savoia, Diego,Umani-Ronchi, Achille
, p. 228 - 234 (2007/10/02)
The reactions of hexyl- and phenylmagnesium bromides with N-acyl and N-alkoxycarbonyl lactams in tetrahydrofuran at -78 deg C have been performed to determine the factors affecting the regioselectivity.N-Pivaloyl γ- and δ-lactams undergo the ring-opening reactions with both Grignard reagents, whereas on the N-benzoyl γ-lactam a complete selectivity is achieved only with phenylmagnesium bromide.The N-Cbz γ- and δ-lactams preferentially react at the exocyclic carbonyl group, especially with hexylmagnesium bromide.The N-Boc five- to eight-membered lactams undergo the ring-opening reaction to give N-Boc-ω-amino ketones, although the efficiency slightly decreases by increasing the ring size.The deprotection of the N-Boc-ω-amino ketones with trifluoroacetic acid easily affords the corresponding five- to seven-membered cyclic imines.Pyridine alkaloids containing the cyclic imine moiety have been prepared by a modified route, exploiting the more easily available pyridyllithium reagents, instead of the corresponding Grignard reagents.
