Highly Diastereo- and Enantioselective Silver-Catalyzed Double [3+2] Cyclization of α-Imino Esters with Isocyanoacetate
作者:Pan-Lin Shao、Jia-Yu Liao、Yee Ann Ho、Yu Zhao
DOI:10.1002/anie.201402788
日期:2014.5.19
Presented herein is a new complexity‐generating method in which both functionalities of α‐imino esters undergo stereoselective cyclization with isocyanoacetates to produce directly linked oxazole‐imidazolines, which can be transformed into highly functionalized α,β‐diamino esters and imidazolinium salts in high diastereo‐ and enantiopurity.
Copper-catalyzed direct coupling of benzoxazin-2-ones with indoles for the synthesis of diverse 3-indolylbenzoxazin-2-ones: access to natural cephalandole A
作者:Rameshwar Prasad Pandit、Jae-Jin Shim、Sung Hong Kim、Yong Rok Lee
DOI:10.1039/c7ra10634c
日期:——
A novel and facile copper-catalyzeddirect coupling for the synthesis of diverse and functionalized 3-indolyl benzoxazin-2-ones from benzoxazin-2-ones and indoles has been developed. This new methodology offers an easy and rapid approach to a variety of 3-indolylbenzo[b][1,4]oxazin-2-ones in high yield. As an application of this protocol, a gram-scale synthesis of naturally occurring cephalandole A
已经开发了一种新颖且容易的铜催化直接偶联反应,用于从苯并恶嗪-2-酮和吲哚合成各种功能化的3-吲哚基苯并恶嗪-2-酮。这种新方法为高产率地制备各种3-吲哚基苯并[ b ] [1,4]恶嗪-2-酮提供了一种简便快捷的方法。作为该方案的应用,还已经完成了天然存在的头孢烯酮A的克级合成。
Direct Asymmetric α‐Selective Mannich Reaction of β,γ‐Unsaturated Ketones with Cyclic α‐Imino Ester: Divergent Synthesis of Cyclocanaline and Tetrahydro Pyridazinone Derivatives
作者:Yu‐Huan Geng、Yuan‐Zhao Hua、Shi‐Kun Jia、Min‐Can Wang
DOI:10.1002/chem.202100284
日期:2021.3.17
The first regio‐, diastereo‐, and enantioselective direct Mannich reaction of β,γ,‐unsaturated ketones with benzoxazinone cyclic imines was enabled by Lewis acid/Brønsted base cooperative catalysis. The dinuclearzinc complex catalyzed the reaction of a broad range of β,γ‐unsaturated ketones to proceed at the α‐site exclusively, leading to corresponding adducts with two consecutive tertiary carbon
路易斯酸/布朗斯台德碱协同催化作用使β,γ-不饱和酮与苯并恶嗪酮环状亚胺进行了第一个区域,非对映和对映选择性的直接曼尼希反应。双核锌络合物催化广泛的β,γ-不饱和酮反应仅在α位进行,从而导致相应的加合物具有两个连续的叔碳立体中心,其非对映异构体比例高达> 20:1,并且通常具有对映选择性在90–99%ee范围内。这些产物被用作一般中间体,用于合成多取代的环茶碱,四氢哒嗪酮和4 H-呋喃[2,3- b ] [1,4]苯并恶嗪衍生物。
Silver-catalyzed cross-dehydrogenative coupling of benzoxazine-2-ones with resorcinol
作者:Yumi Kang、Soomin Jeon、Hayoung Kim、Jonghyeok Han、Garam Choi、Eun-Kyu Sun、Rameshwar Prasad Pandit、Tae-Hyun Kim
DOI:10.1016/j.tetlet.2022.154184
日期:2022.11
Silver-catalyzed cross-dehydrogenative coupling of benzoxazin-2-ones with resorcinol is reported. This method provides an easy and direct C3-arylation of benzoxazin-2-ones at ambient condition at the expenses of inexpensive ammonium persulfate as an oxidant. A radical pathway has been proposed for the transformation.