2006年5月
Synthesis of (Z)-alkene and (E)-fluoroalkene-containing diketopiperazine mimetics utilizing organocopper-mediated reduction-alkylation and diastereoselectivity examination using DFT calculations
JOURNAL OF ORGANIC CHEMISTRY
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- 巻
- 71
- 号
- 11
- 開始ページ
- 4118
- 終了ページ
- 4129
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1021/jo060202z
- 出版者・発行元
- AMER CHEMICAL SOC
We have carefully examined the organocopper-mediated reduction-alkylation of gamma-acetoxy or gamma,gamma-difluoro-alpha,beta- unsaturated-delta-lactams for the synthesis of (Z)-alkene- or (E)-fluoroalkene-containing diketopiperazine mimetics. Reduction of acetates 2, 12, 14, and difluorolactam 18 with higher-order cuprate reagents (Me3CuLi center dot LiI center dot 3LiBr), followed by trapping the resulting metal dienolate with an electrophile in a one-pot procedure gave alpha-alkylated-beta,gamma-unsaturated-delta-lactams in good yields. Because of side-chain steric repulsion, we found that alkylation using relatively large electrophiles such as BnBr gave mostly 3,6-trans isomers by kinetic trapping of metal enolates. On the other hand, MeI-mediated alkylations predominantly provided the unexpected 3,6-cis isomers despite the presence of a bulky benzyl side chain. Based on density functional theory calculations, we concluded that formation of the 3,6-cis isomers was due to the occurrence of oxa-pi-allyllithium complexes 29 and 31.
- リンク情報
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- DOI
- https://doi.org/10.1021/jo060202z
- J-GLOBAL
- https://jglobal.jst.go.jp/detail?JGLOBAL_ID=200902299552984207
- CiNii Articles
- http://ci.nii.ac.jp/naid/80019121708
- PubMed
- https://www.ncbi.nlm.nih.gov/pubmed/16709051
- Web of Science
- https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000237654000011&DestApp=WOS_CPL
- ID情報
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- DOI : 10.1021/jo060202z
- ISSN : 0022-3263
- J-Global ID : 200902299552984207
- CiNii Articles ID : 80019121708
- PubMed ID : 16709051
- Web of Science ID : WOS:000237654000011