Synthesis of Chiral Nine‐Membered N‐Heterocycles through Silver(I)‐Promoted Cycloaddition and Rearrangement from N‐Vinyl‐α,β‐Unsaturated Nitrones with Chiral 3‐Propioloyloxazolidin‐2‐Ones

Abstract

A variety of chiral nine‐membered N‐heterocycles were prepared in moderate to good yields with high diastereoselectivity through a silver(I)‐catalyzed [3+2] cycloaddition and [3,3]‐rearrangement of N‐vinyl‐α, β‐unsaturated nitrones and chiral 3‐propioloyloxazolidin‐2‐ones. Experimental studies showed that silver catalyst promoted the cycloaddition and rearrangement process, and the stereochemistry of the nine‐membered N‐heterocycles was controlled via [3,3]‐rearrangement by chiral oxazolidinone‐auxiliary through a boat‐like transition state. Moreover, the obtained nine‐membered N‐heterocycle diastereomers were converted to chiral pyrrolizines with high diastereoselectivity and pyrrolizine carboxylate was obtained in 54% yield with 90% ee by the removal of chiral auxiliary.

A new type of δ-vinylvalerolactone for palladium-catalyzed cycloaddition: synthesis of nine-membered heterocycles

“…10 Their synthesis has attracted much attention. 11,12 As a powerful tool, several palladium-catalyzed [6+3] and [5+4] cycloaddition reactions have been employed to synthesize nine-membered cyclic compounds, 11 which were established by Trost, 11 a You, 11 b Zhao, 11 d Shibata, 11 e , h Han, 11 i Guo, 11 l Lee, 8 Hu and Wang, 11 k Lu, 11 m and our group. 11 f In these reactions, only π-allylpalladium zwitterionic intermediates from 4-vinyl-1,3-dioxan-2-ones behaved as six-membered synthons to react with N -sulfonyl-1,2,3-triazoles under the catalysis of palladium(0)/rhodium( ii ), implementing [6+3] cycloaddition to give monocyclic nine-membered N , O -heterocycles.…”

Recent Advances on the Synthesis of Nine-Membered N-Heterocycles

“…2017 年, 赵宇教授课题组 [33] 2020 年, Shibata 课题组 [38] 2021 年, 郭武生课题组 [40] 2022 年, 郭红超课题组 [42] 发展了一种新型的 δ-乙 2019 年, 莫冬亮课题组 [46] 利用相似的策略, 通过 2020 年, 莫冬亮课题组 [47] 报道了 Yb(OTf 1 Yb(OTf)3 catalyzed cycloaddition and rearrangement to form nine-membered N-heterocycles a cis/trans ratio, as determined by 1 H NMR analysis of the crude reaction mixture. 2020 年, 莫冬亮课题组 [48] 报道了 Yb(OTf 2021 年, 莫冬亮课题组 [49] 报道了通过银(I)催化的 N-烯基-α,β-不饱和硝酮 72 与手性 3-丙酰噁唑烷-2-酮 80…”

Nitronate-aryne cycloaddition as a concise route to stereochemically complex fused benzisoxazolines and amino alcohols

“…Related [4 + 1]/[3 + 2] and [4 + 2]/[3 + 3] tandem processes were reported by Xiao et al , 6 our group 5,7 and other researchers. 8 These strategies allow rapid generation of molecular and stereochemical complexity, while the resulting bicylic nitroso acetals can be converted to aminoalcohols, that are precursors of natural products (such as pyrrolizidine and indolizidine alkaloids). 1 i – l ,9…”