Copper and Rhodium Relay Catalysis for Selective Access to <i>cis</i>-2,3-Dihydroazepines
作者:You Li、Han Luo、Zongyuan Tang、Yingzi Li、Luan Du、Xiaolan Xin、Shanshan Li、Baosheng Li
DOI:10.1021/acs.orglett.1c02262
日期:2021.8.20
access synthetically challenging cis-2,3-dihydroazepines is reported. The reaction starts with readily available dienals, alkynes, and sulfonyl azides as the substrates and employs copper and rhodium as relay catalysts. Key steps include a copper-catalyzed reaction between an alkyne and a sulfonyl azide to form a triazole intermediate. The subsequent activation of this triazole intermediate by a rhodium
N-Sulfonyl-1,2,3-triazoles react with water in the presence of a rhodium catalyst to produce alpha-amino ketones in high yield. An intermediary alpha-imino rhodium(II) carbenoid undergoes insertion into the O-H bond of water. This transformation formally achieves 1,2-aminohydroxylation of terminal alkynes in a regioselective fashion when combined with the copper(I)-catalyzed 1,3-dipolar cycloaddition with N-sulfonyl azides.