Photoinduced Palladium-Catalyzed Carbofunctionalization of Conjugated Dienes Proceeding via Radical-Polar Crossover Scenario: 1,2-Aminoalkylation and Beyond
作者:Kelvin Pak Shing Cheung、Daria Kurandina、Tetsuji Yata、Vladimir Gevorgyan
DOI:10.1021/jacs.0c03993
日期:2020.6.3
A photoinduced palladium-catalyzed 1,2-carbofunctionalization of conjugateddienes has been developed. This mild modular approach, which does not require employment of exogeneous photosensitizers and external oxidants, allows for efficient and highly regio- and ste-reoselective synthesis of a broad range of allylic amines from readily available 1,3-dienes, alkyl iodides, and amines. Employment of O-
A practical copper-catalyzedhighlyregioselective 1,2-hydrocarboxylation of terminal 1,3-diene with carbon dioxide has been developed. Under mild reactionconditions, this chemistry afforded 2-benzyl-β,γ-unsaturated acid derivatives as products, which are a kind of important unit for bio-active molecules and versatile precursors for organic synthesis, with good functional group tolerance. The key
regio-selective hydroarylation of terminal 1,3-dienes has been developed. This chemistry afforded the terminal alkenyl group containing products, which are a kind of versatile precursor for organic synthesis, from 1,3-dienes by a practical one-step reaction. With good functional group tolerance, this protocol could be used to make a series of bio-active compounds using readily accessible starting materials.
Selective 1,2‐Aminoisothiocyanation of 1,3‐Dienes Under Visible‐Light Photoredox Catalysis
作者:Weisi Guo、Qian Wang、Jieping Zhu
DOI:10.1002/anie.202014518
日期:2021.2.19
N‐aminopyridinium salts and TMSNCS affords 1,2‐aminoisothiocyanation products in a highly chemo‐ and regio‐selective manner under mild photoredox catalytic conditions. Mechanistic studies indicate that the facile isomerization of allyl thiocyanates to allyl isothiocyanates under photocatalytic conditions is responsible for the selective formation of the observed products. The mild isomerization protocol
(including anilines, amines, amino acids, peptides, aryl-1,3-dienes, alyl-1,3-dienes) and tolerates a wide range of functional groups, thus providing a facile and effective approach to access a diverse array of α-substituted β,γ-unsaturated amides. Mechanistic investigations suggested that the hydropalladation of dienes is irreversible, and the insertion of CO into the allyl-Pd species is probably the
共轭二烯的烃基化是合成羰基化合物最有前途但最具挑战性的方法之一。在此,我们报道了前所未有的钯催化的 1,3-二烯与 CO 和胺盐酸盐的支化选择性 3,4-氢氨基羰基化反应,得到β,γ-不饱和酰胺。该反应采用现成的起始材料(包括苯胺、胺、氨基酸、肽、芳基 1,3-二烯、芳基 1,3-二烯)并可耐受多种官能团,因此提供了一种简便有效的方法访问各种α -取代的β,γ-不饱和酰胺。机理研究表明,二烯的加氢钯化反应是不可逆的,将 CO 插入烯丙基钯物种中可能是限速步骤。