Transition-Metal-Free Tunable Chemoselective N Functionalization of Indoles with Ynamides
作者:Alexandre Hentz、Pascal Retailleau、Vincent Gandon、Kevin Cariou、Robert H. Dodd
DOI:10.1002/anie.201402767
日期:2014.8.4
Two unprecedented Nfunctionalizations of indoles with ynamides are described. By varying the electron‐withdrawing group on the ynamide nitrogen atom, either Z‐indolo‐etheneamides or indolo‐amidines can be selectively obtained under the same metal‐free reaction conditions. The scope and synthetic potential of these reactions, as well as some mechanistic insights provided by DFT calculations, are reported
Ynamides are versatile buildingblocks in organic synthesis. However, the synthesis of amino acid-derived ynamides is difficult but in high demand. Herein, we disclose the copper-catalyzed Csp-N coupling of sulfonamide, including amino acid and peptidederivatives, to give ynamides by using alkynyl benziodoxolones with broad functional group tolerance under mild reaction conditions. The electron-rich
The synthesis of a series of 5‐(alkynyl) dibenzothiophenium triflates, prepared from dibenzo[b,d]thiophene 5‐oxide and the corresponding trimethylsilyl‐substituted alkynes is reported. Their structures were determined by X‐ray crystallography, and their reactivities as electrophilic alkynylation reagents evaluated. Their broad substrate scope and functional‐group tolerance illustrate their potential
Synthesis of α-Keto-Imides via Oxidation of Ynamides
作者:Ziyad F. Al-Rashid、Whitney L. Johnson、Richard P. Hsung、Yonggang Wei、Pei-Yuan Yao、Renhei Liu、Kang Zhao
DOI:10.1021/jo8015067
日期:2008.11.21
A de novo preparation of alpha-keto-imides via ynamide oxidation is described. With a number of alkyne oxidation conditions screened, a highly efficient RuO2-NaIO4 mediated oxidation and a DMDO oxidation have been identified to tolerate a wide range of ynamide types. In addition to accessing a wide variety of a-keto-imides, the RuO2-NaIO4 protocol provides a novel entry to the vicinal tricarboryl motif via oxidation of push-pull ynamides, and imido acylsilanes from silyl-substituted ynamides. Chemoselective oxidation of ynamides containing olefins can be achieved by using DMDO, while the RuO2-NaIO4 protocol is not effective. These studies provide further support for the synthetic utility of ynamides.