Diastereoselective Titanocene-Catalyzed Oxidative Cyclization of Bishomoallylic Alcohols
作者:Alessandra Lattanzi、Giorgio Della Sala、Maurizio Russo、Arrigo Scettri
DOI:10.1055/s-2001-16779
日期:——
Bishomoallylic alcohols are converted in good yields and diastereoselectivity into tetrahydrofuranols and tetrahydropyranols by Cp2TiCl2/t-butyl hydroperoxide/activated 4 Å molecular sieves system.
An efficient methodology for the stereoselectivesynthesis of cis‐2,5‐disubstituted pyrrolidines using copper catalyst was developed. The corresponding cis‐2,5‐disubstituted pyrrolidines could be obtained in reasonable yields and with good stereoselectivities in the presence of 4,4′‐di‐tert‐butyl‐2,2′‐bipyridine as ligand and 1‐methyl‐2‐pyrrolidinone as solvent.
Highly Efficient Chemical Kinetic Resolution of Bishomoallylic Alcohols: Synthesis of (<i>R</i>)-Sulcatol
作者:Shui-Ling Chen、Qi-Ying Hu、Teck-Peng Loh
DOI:10.1021/ol048608q
日期:2004.9.1
A highly efficient chemical kinetic resolution of bishomoallylic alcohols was developed when the alcohols underwent In(OTf)(3)-catalyzed 3,5-oxonium-ene-type cyclization with steroidal aldehyde 2. Consistently high enantiomeric excess (up to >99%) was obtained.
MICHAEL, J. P.;TING, P. C.;BARTLETT, P. A., J. ORG. CHEM., 1985, 50, N 14, 2416-2423
作者:MICHAEL, J. P.、TING, P. C.、BARTLETT, P. A.
DOI:——
日期:——
Catalytic Hydroetherification of Unactivated Alkenes Enabled by Proton‐Coupled Electron Transfer
作者:Elaine Tsui、Anthony J. Metrano、Yuto Tsuchiya、Robert R. Knowles
DOI:10.1002/anie.202003959
日期:2020.7.13
We report a catalytic, light‐driven method for the intramolecular hydroetherification of unactivated alkenols to furnish cyclic ether products. These reactions occur under visible‐light irradiation in the presence of an IrIII‐based photoredox catalyst, a Brønsted base catalyst, and a hydrogen‐atom transfer (HAT) co‐catalyst. Reactive alkoxy radicals are proposed as key intermediates, generated by direct
我们报告了一种催化光驱动方法,用于未活化烯醇的分子内加氢醚化以提供环醚产品。这些反应在 Ir III基光氧化还原催化剂、布朗斯台德碱催化剂和氢原子转移 (HAT) 助催化剂存在下在可见光照射下发生。反应性烷氧基被认为是关键中间体,是通过质子耦合电子转移机制直接均裂激活醇 O−H 键而产生的。该方法表现出广泛的底物范围和高官能团耐受性,并且适应多种烯烃取代模式。还提出了证明该催化系统扩展到碳醚化反应的结果。