Oxidation of various cyclic and acyclic ketones under mild conditions with chlorocatecholborane, a bulky pyridine base, and TEMPO to the corresponding α-aminoxylated products in good to excellent yields (52–99%) is described. For enones as substrates, products of a β-chloro-α-aminoxylation are obtained (70–89%).
Diverse Transformation of Vinyl Azides with 2,2,6,6-Tetramethyl-<i>N</i>-oxopiperidinium
作者:Jia-Li Liu、Shu-Wei Wu、Qing-Yan Wu、Feng Liu
DOI:10.1021/acs.joc.8b00954
日期:2018.8.3
(TEMPO+)-mediated three-component diverse transformation of vinyl azides under metal-free conditions is described. The reaction protocols are operationally simple and conducted at ambient temperature, allowing to access various TEMPO-trapped ketones, amides, and α-alkoxyalkyl azides. Preliminary mechanistic studies indicate that an alkene radical cation-mediated radical–radical cross-coupling C–O bond
Persistent radical meets enolates: Catecholboron ketone enolates are oxidized efficiently under mild conditions by treatment with the persistent TEMPO radical. Catecholboron enolates are readily prepared by 1,4‐reduction of α,β‐unsaturated ketones or by transmetalation of silyl enol ethers and zinc enolates with chlorocatecholboranes. Enolate formation and oxidation can be performed as a one‐pot process