Herein a new synthetic route to 1,2-amino alcohols is presented by using C-H amidation of sp(3) methyl C-Hbonds as a key step. Readily available alcohols were employed as starting materials after converting them to removable ketoxime chelating groups. Iridium catalysts were found to be effective for the C-H amidation, and LAH reduction was then used to furnish beta-amino alcohol products.
3. leads to amide products which can be hydrolyzed under mild conditions. The amidation reaction is mild, general and compatible with both primary C−H bonds of tertiary and secondary alcohols, as well as secondary C−H bonds of cyclic secondary alcohols. This method provides an easy access to free 1,2-aminoalcohols after efficient and mild cleavage of the oxime directing group and activated amide.
Selective introduction of fluorine into molecules by the cleavage of inert C−H bonds is of central academic and synthetic interest, yet remains challenging. Given the central role of alcohols in organic chemistry as the most ubiquitous building blocks, a versatile and selectiveC(sp3)−H and C(sp2)−H fluorination of simple alcohols, enabled by novel designed exo‐directing groups, is described. C(sp2)−H
Auxiliary-Assisted Palladium-Catalyzed Direct C(sp<sup>3</sup>)–H Sulfonamidation To Afford 1,2-Amino Alcohol Derivatives
作者:Yi Dong、Gang Liu
DOI:10.1021/acs.joc.6b02975
日期:2017.4.7
An auxiliary-assisted Pd-catalyzed C(sp3)–H sulfonamidation approach using NFSI as both nitrogen source and oxidant to afford 1,2-amino alcohol derivatives is described in this paper. This method is novel and attractive because of its high yields, wide range of substrate scopes, and good tolerance for many functional groups. Oximido and sulfonyl group can be removed with this method.
Catalytic Functionalization of Unactivated sp<sup>3</sup> C–H Bonds via <i>exo</i>-Directing Groups: Synthesis of Chemically Differentiated 1,2-Diols
作者:Zhi Ren、Fanyang Mo、Guangbin Dong
DOI:10.1021/ja3082186
日期:2012.10.17
describe a Pd-catalyzed site-selective functionalization of unactivated aliphatic C-H bonds, providing chemically differentiated 1,2-diols from monoalcohol derivatives. The oxime was employed as both a directing group (DG) and an alcohol surrogate for this transformation. As demonstrated in a range of substrates, the C-H bonds β to the oxime group are selectively oxidized. Besides activation of the methyl