56817-84-6Relevant articles and documents
Methyl Radical Initiated Kharasch and Related Reactions
Tappin, Nicholas D. C.,Renaud, Philippe
, p. 275 - 282 (2021)
An improved procedure to run halogen atom and related chalcogen group transfer radical additions is reported. The procedure relies on the thermal decomposition of di-tert-butylhyponitrite (DTBHN), a safer alternative to the explosive diacetyl peroxide, to produce highly reactive methyl radicals that can initiate the chain process. This mode of initiation generates byproducts that are either gaseous (N2) or volatile (acetone and methyl halide) thereby facilitating greatly product purification by either flash column chromatography or distillation. In addition, remarkably simple and mild reaction conditions (refluxing EtOAc during 30 minutes under normal atmosphere) and a low excess of the radical precursor reagent (2 equivalents) make this protocol particularly attractive for preparative synthetic applications. This initiation procedure has been demonstrated with a broad scope since it works efficiently to add a range of electrophilic radicals generated from iodides, bromides, selenides and xanthates over a range of unactivated terminal alkenes. A diverse set of radical trap substrates exemplifies a broad functional group tolerance. Finally, di-tert-butyl peroxyoxalate (DTBPO) is also demonstrated as alternative source of tert-butoxyl radicals to initiate these reactions under identical conditions which gives gaseous by-products (CO2). (Figure presented.).
KETONE-CONTAINING CONTROLLED RADICAL INITIATORS FOR POLYMERIZATION REACTIONS
-
Paragraph 0204; 0205, (2020/12/08)
Controlled radical initiators that are ketone-containing dithiocarbamate or ketone-containing dithiocarbonate compounds are used to form polymeric materials that have a single polymeric block or multiple polymeric blocks. Reaction mixtures containing controlled radical initiators and various ethylenically unsaturated monomers, polymeric materials formed from the reaction mixtures, crosslinkable compositions containing the polymeric materials, crosslinked compositions formed from the crosslinkable compositions, and articles containing the polymeric materials, the crosslinkable compositions, or the crosslinked compositions are provided.
Efficient Synthesis of N-Benzyloxycarbonyl-2-aminoalkanesulfonyl Chlorides with Functionalized Side Chains
Abdellaoui, Hassane,Chen, Xingpeng,Xu, Jiaxi
, p. 2250 - 2256 (2017/05/05)
N-Benzyloxycarbonyl (Cbz)-protected 2-aminoalkanesulfonyl chlorides are useful building blocks for the synthesis of sulfonopeptides, which are receptor ligands and enzyme inhibitors, and are prepared by the coupling reaction of N-protected aminoalkanesulfonyl chlorides with amino acid or peptide esters. Various N-Cbz-protected 2-aminoalkanesulfonyl chlorides with functionalized side chains were synthesized through the radical addition of different xanthates to benzyl N-allylcarbamate and subsequent oxidative chlorination with tert-butyl hypochlorite under neutral conditions. A mechanism for the oxidative chlorination is proposed. This is a useful and convenient strategy for the synthesis of N-Cbz-protected 2-aminoalkanesulfonyl chlorides with diverse functionalized side-chains.
