Copper-Catalyzed and Indium-Mediated Methoxycarbonylation of Unactivated Alkyl Iodides with Balloon CO
作者:Yanchi Chen、Lei Su、Hegui Gong
DOI:10.1021/acs.orglett.9b01573
日期:2019.6.21
This work emphasizes the synthesis of alkyl esters via Cu-catalyzed and In-mediated alkoxycarbonylation of unactivatedalkyliodides in the presence of In or InI. The reactions were suitable for the preparation of primary, secondary, and even tertiary alkyl esters, representing an exceptionally rare example for the creation of quaternary carbon centers upon formation of esters. The preliminary mechanistic
这项工作强调在In或InI的存在下,通过Cu催化和In介导的未活化烷基碘的烷氧基羰基化来合成烷基酯。该反应适合于伯,仲,甚至叔烷基酯的制备,代表了在形成酯时生成季碳中心的极为罕见的例子。初步的机理研究表明,涉及烷基自由基,而Cu / In / CO在羰基化事件中起着协同作用。
Asymmetric transfer hydrogenation of unsaturated ketones; factors influencing 1,4- vs 1,2- regio- and enantioselectivity, and alkene vs alkyne directing effects
作者:Thomas H. Hall、Hannah Adams、Vijyesh K. Vyas、K.L. Michael Chu、Martin Wills
DOI:10.1016/j.tet.2020.131771
日期:2021.1
A detailed study has been completed on the asymmetric transferhydrogenation (ATH) of a series of enones using Ru(II) catalysts. Electron-rich rings adjacent to the CO group reduce the level of CO reduction compared to CC. The ATH reaction can readily discriminate between double and triple bonds adjacent to ketones, reducing the double bond but leaving a triple bond intact in the major product.
Regioselective Hydrohydroxyalkylation of Styrene with Primary Alcohols or Aldehydes via Ruthenium-Catalyzed C−C Bond Forming Transfer Hydrogenation
作者:Hongde Xiao、Gang Wang、Michael J. Krische
DOI:10.1002/anie.201609056
日期:2016.12.23
Transferhydrogenative coupling of styrene with primaryalcohols using the precatalyst HClRu(CO)(PCy3)2 modified by AgOTf or HBF4 delivers branched or linear adducts from benzylic or aliphatic alcohols, respectively. Related 2‐propanol mediated reductive couplings also are described.
A new Mn‐catalyzed alkylation of secondary alcohols with non‐activated alcohols is presented. The use of a stable and well‐defined manganese pincer complex, stabilized by a PNN ligand, together with a catalytic amount of base enabled the conversion of renewable alcohol feedstocks to a broad range of higher‐value alcohols in good yields with water as the sole byproduct. The strategy eliminates the need
herein an unprecedented highly efficient Guerbet‐type reaction at room temperature (catalytic TON up to >6000). This β‐alkylation of secondary methyl carbinols with primary alcohols has significant advantage of delivering higher‐order secondary alcohols in an economical, redox‐neutral fashion. In addition, the first enantioselective Guerbet reaction has also been achieved using a commercially available