Copper‐Catalyzed Formal [2+2+1] Heteroannulation of Alkenes, Alkylnitriles, and Water: Method Development and Application to a Total Synthesis of (±)‐Sacidumlignan D
作者:Tu M. Ha、Claire Chatalova‐Sazepin、Qian Wang、Jieping Zhu
DOI:10.1002/anie.201604528
日期:2016.8
A copper‐catalyzed three‐component reaction of alkenes, alkylnitriles, and water affords γ‐butyrolactones in good yields. The domino process involves an unprecedented hydroxy‐cyanoalkylation of alkenes and subsequent lactonization with the creation of three chemical bonds and a quaternary carbon center. The synthetic potential of this novel [2+2+1] heteroannulation reaction was illustrated by a concise
Electroreductive coupling of aromatic ketones, aldehydes, and aldimines with α,β-unsaturated esters: Synthesis of 5-aryl substituted γ-butyrolactones and lactams
作者:Naoki Kise、Yusuke Hamada、Toshihiko Sakurai
DOI:10.1016/j.tet.2017.01.013
日期:2017.2
The electroreductive intermolecular coupling of aromatic ketones and aldehydes with α,β-unsaturated esters in the presence of TMSCl gave the adducts as γ-trimethylsiloxy esters. The detrimethylsilylation of the adducts with TBAF afforded 5-aryl substituted γ-butyrolactones. The electroreductive coupling of N-(4-methoxyphenyl)-1-arylmethaneimines with methyl acrylate in the presence of TMSCl gave the
Enantioselectivebromolactonization of trisubstituted olefinicacids producing synthetically useful chiral lactones with two contiguous asymmetric centers has remained mainly unexplored except for the 6‐exo cyclization mode. In this work, the 5‐exo‐ and 6‐endo modes of bromocyclization of trisubstituted olefinicacids were enabled for the first time using N‐bromosuccinimide and a pyridyl phosphoramide
Access to Alkyl-Substituted Lactone via Photoredox-Catalyzed Alkylation/Lactonization of Unsaturated Carboxylic Acids
作者:Wanxing Sha、Shengyang Ni、Jianlin Han、Yi Pan
DOI:10.1021/acs.orglett.7b02899
日期:2017.11.3
N-hydroxyphthalimide esters as alkylation reagents has been developed. Varieties of redox-active esters derived fromaliphatic carboxylic acids were proved viable in this method, affording alkyl substituted lactones in moderate to good yields. This redox-neutral procedure features mild conditions and operational simplicity, which provides a new strategy for the synthesis of alkyl substituted lactones.
Trivedi; Nargund, Journal of the University of Bombay, Science: Physical Sciences, Mathematics, Biological Sciences and Medicine, 1941, vol. 10/3A, p. 99