Alcohol triphenylmethyl (trityl) ethers were readily and efficiently transformed into the corresponding acetates by reaction with acetyl bromide. Triphenylmethyl ethers can also be transformed into the corresponding substituted acetates in high yields by the use of various substituted acetyl chlorides combined with sodium iodide.
Improved Process for the Palladium-Catalyzed C–O Cross-Coupling of Secondary Alcohols
作者:Hong Zhang、Paula Ruiz-Castillo、Alexander W. Schuppe、Stephen L. Buchwald
DOI:10.1021/acs.orglett.0c01668
日期:2020.7.17
An improved protocol for the Pd-catalyzed C–O cross-coupling of secondaryalcohols is described. The use of biaryl phosphine L2 as the ligand was key to achieving efficient cross-coupling of (hetero)aryl chlorides with only a 20% molar excess of the alcohol. Additionally, we observed an unusual reactivity difference between an electron-rich aryl bromide and the analogous aryl chloride, and deuterium-labeling
Potential antiinflammatory agents. IV. Stereoselective synthesis of 6-chloro-5-(3'- and 4'-hydroxycyclohexyl)indan-1-carboxylic acids related to metabolites of 6-chloro-5-cyclohexylindan-1-carboxylic acid (TAI-284).
In the course of synthetic study of metabolites of a new potent antiinflammatory agent, 6-chloro-5-cyclohexylindan-1-carboxylic acid (TAI-284), 5-(cis-and trans-3'-hydroxy-cyclohexyl) indan-1-carboxylic acids (25 and 26) and 5-(cis- and trans-4'-hydroxycyclohexyl) indan-1-carboxylic acids (17 and 16) were stereoselectively prepared by sodium borohydride reduction (equatorial alcohol formation) and catalytic hydrogenation (axial alcohol formation) of the corresponding 3'-oxo and 4'-oxo compounds (24 and 15), respectively. Chlorination of 25, 26, 17 and 16 with molecular chlorine in acetonitrile gave their 6-chloro derivatives (27, 28, 21 and 20), which were correlated with metabolites of TAI-284. Of these indans, 3'-hydroxy compounds (25-28) were prepared as a pair of racemic diastereoisomers.
Iron-catalysed cross-coupling of halohydrins with aryl aluminium reagents: a protecting-group-free strategy attaining remarkable rate enhancement and diastereoinduction
Non-protected halohydrins are cross-coupled with aryl aluminium reagents to produce aryl alkanols in the presence of the iron–bisphosphine catalysts. Remarkable reaction rate enhancement and diastereoinduction are realized by the in situ generated aluminium alkoxides, offering a new method for the reactivity and selectivity control of the iron-catalysed cross-coupling reaction.
A one-step and chemoselective conversion of silyl-protected alcohols into the corresponding acetates
作者:Takeshi Oriyama、Mihoko Oda、Junko Gono、Gen Koga
DOI:10.1016/s0040-4039(00)73040-1
日期:1994.3
A reagent system of acetyl bromide combined with a catalytic amount of tin(II) bromide cleaves readily trialkylsilyl ethers to give the corresponding acetates in high yields under very mild conditions.