Abstract
Nucleophilic aromatic substitution (SNAr) reactions of ortho-alkoxyarylcarboxylic esters by C-, N-, and O-nucleophiles, developed in our laboratory, are reviewed. Aryl Grignard reagents efficiently displaced the 1-methoxy group of 1-methoxy-2-naphthoates to afford the corresponding biaryls in excellent yields ; isopropyl ester is bulky enough to prevent the Grignard addition to the ester carbonyl function. 2-Methoxybenzoic esters derived from 2,6-dialkylphenols also underwent the SNAr reaction by proper choice of the bulk of the 2,6-dialkyl-substituents. High levels of asymmetric induction were achieved in these reactions by use of an enantiomeric menthoxy leaving group. As the electrondonating ability of the carbanion species increased, 1,4- or 1,6-conjugate addition of the nucleophiles to the 2-methoxybenzoates was found to compete with the SNAr reaction. Triarylamines were conveniently prepared by the reaction of a 2- or 4-fluorobenzoate with lithium diarylamides in THF-HMPA. 2-Sulfonyl- as well as 2-phosphinoyl-substituted 1-methoxynaphthalenes also underwent the SNAr reaction. Factors affecting the activating power of the 2-substituents are discussed.
Original language | English |
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Pages (from-to) | 121-131 |
Number of pages | 11 |
Journal | Yuki Gosei Kagaku Kyokaishi/Journal of Synthetic Organic Chemistry |
Volume | 55 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1997 |
Keywords
- Aminophosphine
- Asymmetric ring-opening reaction
- Asymmetric synthesis
- Biaryl
- Conjugate addition
- Cyclophane
- Lignan
- Nucleophilic aromatic substitution
- Triarylamine
ASJC Scopus subject areas
- Organic Chemistry