Synthesis of Chiral Propargylamines, Chiral 1,2-Dihydronaphtho[2,1-b]furans and Naphtho[2,1-b]furans with C-Alkynyl N,N'-di-(tert-butoxycarbonyl)-aminals and β-Naphthols

Ningning Man; Yuming Li; Jiyang Jie; Hongyun Li; Haijun Yang; Yufen Zhao; Hua Fu

doi:10.1002/chem.202102040

Synthesis of Chiral Propargylamines, Chiral 1,2-Dihydronaphtho[2,1-b]furans and Naphtho[2,1-b]furans with C-Alkynyl N,N'-di-(tert-butoxycarbonyl)-aminals and β-Naphthols

Chemistry. 2021 Sep 6;27(50):12884-12889. doi: 10.1002/chem.202102040. Epub 2021 Jul 22.

Authors

Ningning Man¹, Yuming Li¹, Jiyang Jie¹, Hongyun Li¹, Haijun Yang¹, Yufen Zhao¹, Hua Fu¹

Affiliation

¹ Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, China.

PMID: 34133047
DOI: 10.1002/chem.202102040

Abstract

Chiral phosphoric acid-catalyzed couplings of C-alkynyl N,N'-di-(tert-butoxycarbonyl)-aminals with β-naphthols led to chiral propargylamines in moderate to high yields with high to excellent enantioselectivity, in which the reactions underwent sequential chiral phosphoric acid-catalyzed in situ formation of N-(tert-butoxycarbonyl)-imines (N-Boc-imines) from the aminals, and 1,2-addition of β-naphthols to the N-Boc-imines. Chiral 1,2-dihydronaphtho[2,1-b]furans and naphtho[2,1-b]furans were prepared with satisfactory results when 10 mol% AgOAc and 20 mol% 2,6-lutidine or 1.2 equiv. of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) were added to the resulting chiral propargylamines solution, respectively.

Keywords: asymmetric synthesis; chiral dihydronaphtho[2,1-b]furans; chiral phosphoric acid; chiral propargylamines; naphtho[2,1-b]furans.