17983-58-3Relevant academic research and scientific papers
One-Pot Reductive 1,3-Dipolar Cycloaddition of Secondary Amides: A Two-Step Transformation of Primary Amides
Huang, Pei-Qiang,Lang, Qi-Wei,Hu, Xiu-Ning
, p. 10227 - 10235 (2016)
The one-pot reductive 1,3-dipolar cycloaddition of secondary aromatic N-(trimethylsilylmethyl)amides with reactive dipolarophiles is reported. The method relies on the in situ generation of nonstabilized NH azomethine ylide dipoles via amide activation with triflic anhydride, partial reduction with 1,1,3,3-tetramethyldisiloxane (TMDS), and desilylation with cesium fluoride (CsF). Running under mild conditions, the reaction tolerated several sensitive functional groups and provided cycloadducts in 71-93% yields. The use of less reactive dipolarophile methyl acrylate led to the cycloadduct in only 40% yield. A (Z) geometric intermediate of NH-azomethine 1,3-dipole was postulated to account for the observed higher yields and higher cis diastereoselectivity for the substrates bearing an electron-withdrawing group. This model features an unconventional cyclic transition state via carbanion-aryl ring interaction. Because the starting secondary amides can be prepared from common primary amides, the current method also constitutes a two-step transformation of primary amides.
S-TRIAZINE DERIVATIVES CONTAINING AT LEAST TWO PARTICULAR SILANE AMINOBENZOATE OR SILANE AMINOBENZAMIDE GROUPS; PHOTOPROTECTIVE COSMETIC COMPOSITIONS CONTAINING THESE DERIVATIVES; USES OF THE SAID S-TRIAZINE DERIVATIVES
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Page/Page column 36-37, (2009/05/28)
The invention relates to novel s-triazine derivatives containing at least two particular silane aminobenzoate or silane aminobenzamide groups and to their cosmetic uses. The invention also relates to photoprotective compositions comprising s-triazine deri
