Without the formation of inseparable regioisomers, various substituted phenol derivatives 2 and benzene derivatives 4 were prepared through RCM-tautomerization and RCM-dehydration protocols. A new synthetic route to precursors 1 and 3 enabled efficient access to these aromatic compounds.
Alkenyl (or aryl) iodide (or bromide) is readily reduced with CrCl2 is N,N-dimethylformamide at 25°C to gice the corresponding organochromium species which adds selectively to an aldehyde moiety without affecting the coexisting ketone or cyano group of the substrate.
Gold-Catalyzed Highly Regioselective Oxidation of C−C Triple Bonds without Acid Additives: Propargyl Moieties as Masked α,β-Unsaturated Carbonyls
作者:Biao Lu、Chaoqun Li、Liming Zhang
DOI:10.1021/ja1072614
日期:2010.10.13
Gold-catalyzed intermolecular oxidations of internal alkynes have been achieved with high regioselectivities using 8-alkylquinoline N-oxides as oxidants and in the absence of acid additives. Synthetically versatile α,β-unsaturated carbonyls are obtained in good to excellent yields and with excellent E-selectivities. A range of functional groups such as THP, MOMO, N(3), OTBS, and N-Boc are tolerated
使用 8-烷基喹啉 N-氧化物作为氧化剂并且在没有酸添加剂的情况下,已经以高区域选择性实现了内部炔烃的金催化分子间氧化。合成通用的 α,β-不饱和羰基化合物以良好到极好的收率和极好的 E 选择性获得。可以容忍一系列功能组,例如 THP、MOMO、N(3)、OTBS 和 N-Boc。该反应允许 α,β-不饱和羰基被掩蔽为炔丙基部分,从而为复杂结构合成中可能遇到的这些官能团的相容性问题提供了实用的解决方案。
Gold‐Catalyzed Double Cycloisomerization of 1‐Ene‐4,10‐diynyl Esters to Bicyclo[6.3.0]undeca‐2,4,9‐trienyl Esters
作者:Mitch Mathiew、Javey Khiapeng Tan、Philip Wai Hong Chan
DOI:10.1002/anie.201809376
日期:2018.10.22
trienyl esters efficiently from gold(I)‐catalyzed Rautenstrauch rearrangement/1,5‐hydride shift/8‐endo‐dig cyclization of 1‐ene‐4,10‐diynyl esters is described. The suggested double cycloisomerization mechanism delineates the first example of an unactivated all‐carbon tethered 1,7‐enyne, either preformed or formed in situ, which undergoes an 8‐endo‐dig cyclization pathway to give a cyclooctane motif
Silver Triflate-Catalyzed Cyclopropenation of Internal Alkynes with Donor-/Acceptor-Substituted Diazo Compounds
作者:John F. Briones、Huw M. L. Davies
DOI:10.1021/ol201503j
日期:2011.8.5
Silver triflate was found to be an efficient catalyst for the cyclopropenation of internal alkynes using donor-/acceptor-substituted diazo compounds as carbenoid precursors. Highly substituted cyclopropenes, which cannot be synthesized directly via rhodium(II)-catalyzed carbenoid chemistry, can now be readily accessed.