Guiding the nitrogen nucleophile to the middle: palladium-catalyzed decarboxylative cyclopropanation of 2-alkylidenetrimethylene carbonates with isocyanates
作者:Ryo Shintani、Kohei Moriya、Tamio Hayashi
DOI:10.1039/c0cc05308b
日期:——
A palladium-catalyzed decarboxylative cyclopropanation of 2-alkylidenetrimethylene carbonates with isocyanates is described to form oxazolidinones of (1-aminocyclopropyl)methanols with high selectivity. The site of nucleophilic attack is directed by connecting the two reaction components and by employing an electron-deficient triarylphosphine ligand.
In this paper, a palladium-catalyzed [4 + 2] cycloaddition of 5-methylene-1,3-oxazinan-2-ones with 4-arylidene-2,4-dihydro-3H-pyrazol-3-ones has been developed to produce spiropyrazolones in high yields with excellent diastereoselectivities in nearly all cases. The cycloaddition reaction was scaled-up without significant loss of yield, and its synthetic utility has been demonstrated by further transformations
在本文中,开发了钯催化的 [4 + 2] 环加成 5-methylene-1,3-oxazinan-2-ones 与 4-arylidene-2,4-dihydro-3 H -pyrazol-3-ones以高产率生产螺吡唑酮,几乎在所有情况下都具有出色的非对映选择性。环加成反应在没有显着产率损失的情况下按比例放大,其合成效用已通过产物的进一步转化得到证明。首次将钯催化下N-Ts环状氨基甲酸酯的反应类型扩展为包括[4+2]环加成。
Pd-Catalyzed [4 + 1] Annulation Strategy to Functionalized 4-Methyleneproline Derivatives
作者:Jiaxin Han、Wenzheng Gao、Joseph P. A. Harrity
DOI:10.1021/acs.joc.3c02178
日期:2024.2.2
A Pd-catalyzed formal [4 + 1] cycloaddition reaction of sulfurylides and in situ-generated Pd-stabilized zwitterions offers a convenient route to a series of functionalized proline derivatives. The utility of this method is demonstrated by a gram-scale synthesis and chemoselective functionalization of a proline-based derivative.
has been successfully developed, which gives a powerful and straightforward synthetic strategy for the construction of novel gem-difluorinated spirocyclic compounds, 6,6-difluoro-5-oxa/azaspiro[2.4]heptanes. The scope of gem-difluoroalkenes can be extended to styrenes, acrylic esters, and acrylamides to realize the installment of various functional groups and different heteroatoms on the spirocyclic