Synthesis of 3- and 4-substituted cyclic α-amino acids structurally related to ACPD
作者:Francisco Alonso、Irene Micó、Carmen Nájera、José M. Sansano、Miguel Yus、Jesús Ezquerra、Belén Yruretagoyena、Ismael Gracia
DOI:10.1016/0040-4020(95)00586-w
日期:1995.9
The preparation of 3-substituted cyclopentanones 12-16, 4-substituted cyclohexanones 23–28 and cycloheptanones 38–41 is described. Substituents in the cycloalkanones are carboxylate, phosphonate or tetrazole groups, separated from the ring by a 0, 1, 2, or 3 carbon atoms chain. These cycloalkanones have been transformed into α-amino acids 9–11 by hydrolysis of the corresponding hydantoin derivatives
Dynamic Kinetic Sensitization of β‐Dicarbonyl Compounds—Access to Medium‐Sized Rings by De Mayo‐Type Ring Expansion
作者:Tiffany O. Paulisch、Lukas A. Mai、Felix Strieth‐Kalthoff、Michael J. James、Christian Henkel、Dirk M. Guldi、Frank Glorius
DOI:10.1002/anie.202112695
日期:2022.1.26
A photocatalyzed ring expansion procedure for a two-carbon homologation of cyclic carbonyl compounds, towards medium-sized ring systems, is introduced. Key to success is the catalyst fac-[Ir(CF3-pmb)3] (ET=73.3 kcal mol−1), which allows for selective activation of the substoichiometric enol species. The mechanism has been corroborated by time-resolved spectroscopy and enabled a full kinetic analysis
介绍了一种光催化扩环过程,用于环状羰基化合物的双碳同系化,朝向中型环系统。成功的关键是催化剂fac -[Ir(CF 3 -pmb) 3 ] ( E T =73.3 kcal mol -1 ),它允许选择性活化亚化学计量的烯醇物质。该机制已被时间分辨光谱证实,并能够对动态动力学敏化情景进行全面的动力学分析。