Increased Yields and Simplified Purification with a Second-Generation Cobalt Catalyst for the Oxidative Formation of <i>trans</i>-THF Rings
作者:Cory Palmer、Nicholas A. Morra、Andrew C. Stevens、Barbora Bajtos、Ben P. Machin、Brian L. Pagenkopf
DOI:10.1021/ol9023375
日期:2009.12.17
The synthesis of a second-generation cobalt catalyst for the formation of trans-THF products via the Mukaiyama aerobic oxidative cyclization is reported. Two procedures have been developed with the new water-soluble catalyst that give superior yields and greatly simplify purification compared to the previous catalysts.
Rh(<scp>i</scp>)-catalyzed site-selective hydroacylation of alkenyl-bearing allylic alcohols with non-chelating aldehydes controlled by <i>in situ</i> generated carbonyl group
作者:Fu-Gang Wang、Fei-Yuan Gong、Juan Cao、Ji-Cong Wang、Kai-Qiang Tian、Jinbo Zhao、Hong-Shuang Li
DOI:10.1039/d2nj04607e
日期:——
A rhodium(I)-catalyzed regioselective hydroacylation of alkenyl-bearing allylic alcohols with simple aldehydes for the preparation of diverse 1,5-diketones is described. Mechanistic investigation suggests that this transformation might proceed through redox isomerization of the allylic alcohol followed by hydroacylation of the resulting enone with aldehyde involving a stable six-membered rhodacycle
描述了一种铑 ( I ) 催化的带有烯基的烯丙醇与简单醛的区域选择性加氢酰化反应,用于制备不同的 1,5-二酮。机理研究表明,这种转化可能通过烯丙醇的氧化还原异构化,然后用醛将所得的烯酮加氢酰化,包括稳定的六元罗丹环中间体来进行。该协议强调了原位生成的羰基在控制分子内烯烃部分的位点选择性中的作用。