Palladium Catalyzed Cascade C-H Functionalization and NBS Mediated Thiocyanation Strategies for the Synthesis of Biologically Relevant Heterocycles and PACs

Abstract

本篇論文敘述了兩個部分。Part Ι分成三個部分。A部分闡述了鈀催化級聯C-H官能基化學反應的概況。在這個部分簡介了鈀催化級聯反應包含C-H鍵官能化，末端炔烴的C-H鍵官能化反應和鈀催化的C-H鍵烯基化。B部分描述了利用鈀金屬催化串聯C-H鍵官能化/環化策略來合成5種羥基苯並呋喃衍生物。在這個部分通過鈀催化的C-C / C-O鍵反應成功合成出5個羥基苯並呋喃衍生物。此外我們也描述了苯醌作為反應物和氧化劑的雙重作用。在C部分，表示鈀催化的分子內環化/脫氰氫化C-H鍵烯基化來合成苯[b]三亞苯衍生物。在乙酸銅作為氧化劑下利用鈀進行催化反應，有效的將苯氧乙酰甲基縮合產物（2Z，2'Z）-3,3' - （[1,1'-聯苯] -2,2'-二基）二（2-苯基丙烯腈）轉化為苯並[b] 苯並菲-9-腈衍生物。 第二部分分為兩個部分。A部分是描述異噁唑啉N-氧化物。此外，我們也研究了各種C-S鍵形成的反應，也描述了硫氰化反應和硫氰酸化試劑的合成應用。此外，也討論了異噻唑類化合物的合成和應用。B部分，描述了“N-溴代琥珀酰亞胺介導的環己烯稠合異噁唑啉N-氧化物的硫氰化反應這是一種有效的新穎異噻唑衍生物的方法”。 此方法涉及原位生成的用作硫氰酸化劑的N-硫代氰基琥珀酰胺。此外，這種含SCN的產物進一步用於合成新的環己酮環稠合的異噻唑衍生物。

The content of this dissertation is divided into two parts. Part Ι is subdivided into three sections. Section A illustrates the overview on Palladium catalyzed cascade C-H functionalization reactions. This section also described a brief survey on Palladium catalyzed cascade reactions involving C-H bond functionalization, C-H bond functionalization reactions of terminal alkynes and Palladium catalyzed C-H bond alkenylation protocols. Section B describes “The study of palladium-catalyzed tandem C−H bond functionalization/cyclization strategy for the synthesis of 5-Hydroxybenzofuran Derivatives”. In this section, the synthesis of 5-Hydroxybenzofuran Derivatives was achieved via palladium-catalyzed C-C/C-O bond formation reactions. Additionally, we also described the dual role of benzoquinone as a reactant as well as the oxidant. Section C demonstrates the “Palladium-Catalyzed Intramolecular Annulation/ Decyanogenative C-H bond Alkenylation Strategy for the Synthesis of Benzo[b] triphenylene derivatives”. Here, easily accessible knoevenagel condensation product (2Z,2'Z)-3,3'-([1,1'-biphenyl]-2,2'-diyl) bis(2-phenylacrylonitrile) converted efficiently into benzo[b]triphenylene-9-carbonitrile derivatives under palladium catalysis in the presence of copper acetate as an oxidant. Part II is divided into two sections. Section A is about the Overview on Isoxazoline N-oxides. Further, we also studied various C-S bond formation reactions, also described thiocyanation reactions and thiocyanating reagents and their synthetic utility in this section. additionally, Isothiazoles: synthesis and applications were discussed. Section B demonstrates the “N-Bromosuccinimide-Mediated Thiocyanation of Cyclohexene-Fused Isoxazoline N-Oxides: An Efficient Approach Towards the Novel Isothiazole Derivatives”. Present strategy involves In-situ generated N-thiocyanosuccinamide utilized as a thiocyanation agent. Moreover, this SCN containing product was further utilized for the synthesis of novel cyclohexanone ring fused isothiazole derivatives.