制备了一系列的烯丙基酰胺,并研究了它们在金催化下的环化反应。观察到六元环1,3-恶嗪的形成。源自亚丙基的远端CC双键的分子内加氢胺化的二氢吡咯是次要的副产物。通过原位31 P NMR光谱进行的机理研究表明,在每种情况下,转化过程中仅增加了一种。通过对不同烯丙基金(I)物种的计算研究,可以将其指定为在空间位阻较少的亚甲基末端带有金催化剂的σ-烯丙基金。该中间体的区域特异性氘化脱氢证实了催化循环最后一步的S E '型机制。
Gold Catalysis: 1,3-Oxazines by Cyclisation of Allene Amides
作者:A. Stephen K. Hashmi、Andreas M. Schuster、Sebastian Litters、Frank Rominger、Markus Pernpointner
DOI:10.1002/chem.201100132
日期:2011.5.9
A series of allene amides was prepared and their gold‐catalysed cyclisation was investigated. The formation of six‐memberedrings, 1,3‐oxazines, was observed. Dihydropyrroles originating from intramolecular hydroamination of the distal CC double bonds of the allenes were minor side products. Mechanistic studies by in situ 31P NMR spectroscopy showed only one additional species during the conversion
制备了一系列的烯丙基酰胺,并研究了它们在金催化下的环化反应。观察到六元环1,3-恶嗪的形成。源自亚丙基的远端CC双键的分子内加氢胺化的二氢吡咯是次要的副产物。通过原位31 P NMR光谱进行的机理研究表明,在每种情况下,转化过程中仅增加了一种。通过对不同烯丙基金(I)物种的计算研究,可以将其指定为在空间位阻较少的亚甲基末端带有金催化剂的σ-烯丙基金。该中间体的区域特异性氘化脱氢证实了催化循环最后一步的S E '型机制。
Catalyst-Directed Divergent Catalytic Approaches to Expand Structural and Functional Scaffold Diversity via Metallo-Enolcarbene Intermediates
作者:Kuiyong Dong、Haifeng Zheng、Yongliang Su、Ahmad Humeidi、Hadi Arman、Xinfang Xu、Michael P. Doyle
DOI:10.1021/acscatal.1c01051
日期:2021.4.16
with either Au(I) or Cu(I) catalysis or [3 + 2]-cycloaddition with a Cu(II) catalyst; and direct cycloaddition with the C═N bond of methylenedihydrooxazoles followed by rearrangement forming multiply substituted pyrroles in the presence of a silver catalyst. Allylic aromatization via vinylogous addition selectively delivers aromatic oxazole derivatives from methylenedihydrooxazoles, and when aromatization