TMSOTf-mediated approach to 1,3-oxazin-2-one skeleton through one-pot successive reduction-[4 + 2] cyclization process of imides with ynamides
作者:Chen-Chen Zhang、Zhi-Peng Huo、Mei-Lin Tang、Yong-Xi Liang、Xun Sun
DOI:10.1016/j.tetlet.2021.152946
日期:2021.3
A one-pot approach to access functionalized 1,3-oxazin-2-one skeleton has been developed through successive reduction and subsequent [4 + 2] cyclization process of N-Boc lactams with ynamides by TMSOTf. As a result, a number of five to seven membered ring fused bicyclic [1,2-c][1], [3]oxazin-1-ones 12a-m and tricyclic derivatives 13a-f were obtained in moderate to excellent yields with excellent regioselectivities
Enantioselective Synthesis of Tertiary α,α-Diaryl Carbonyl Compounds Using Chiral <i>N,N′</i>-Dioxides under Umpolung Conditions
作者:Tae-Woong Um、Girim Lee、Seunghoon Shin
DOI:10.1021/acs.orglett.0c00333
日期:2020.3.6
addition of the chiral N,N'-dioxide into ynamides generated enolonium ions in situ which underwent enantioselective alkylation by indoles, pyrroles, and phenols, without racemization of the formed tertiary center. This external oxidant approach allows for the use of unmodified nucleophiles and does not leave trace groups from the oxidant, which significantly increases the synthetic efficiency and the
A rare-earth salt Yb(OTf)3-catalyzed regioselective hydroamination of ynamides with anilines and p-toluenesulfonamide has been developed. This protocol provided facile access to a diverse range of amidines with good functional group tolerance in moderate to high yields.
The synthesis of ynamides in water was achieved by a micellarcatalysis strategy using rosin‐based surfactant APGS‐550‐M, which can be easily prepared from natural abundant biomass.
Synthesis of Amide Enol Carbamates and Carbonates through Cu(OTf)<sub>2</sub>-Catalyzed Reactions of Ynamides with <i>t</i>-Butyl Carbamates/Carbonates
作者:Pan Han、Zhuo-Ya Mao、Ming Li、Chang-Mei Si、Bang-Guo Wei、Guo-Qiang Lin
DOI:10.1021/acs.joc.9b03512
日期:2020.4.3
A highly regioselective approach to access amide enol carbamates and carbonates 5a–5c′, 7a–7h, and 9 was developed through Cu(OTf)2-catalyzed reactions of ynamides 4 with t-butyl carbamates 2 and 8 and t-butyl carbonates 6. Moreover, this strategy was successfully applied to generate amide enol carbamates 11a–11s and 14a–14f from imides 10 and 13 with ynamides through an N-Boc cleavage–addition ring-opening