Kvaskoff David, Becker Jürgen, Wentrup Curt
†School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia.
‡Fachbereich Chemie der Philipps-Universität Marburg, D-35037 Marburg, Germany.
J Org Chem. 2015 May 15;80(10):5030-4. doi: 10.1021/acs.joc.5b00412. Epub 2015 May 7.
1-Azulenylcarbene 18 has been generated from 5-(1-azulenyl)tetrazole and the sodium salt of azulene-1-carbaldehyde tosylhydrazone using the falling solid flash vacuum pyrolysis (FS-FVP) method. The principal products, which are also formed from both 1- and 2-naphthylcarbenes, cyclobuta[de]naphthalene 6, cyclopenta[cd]indene 16, and benzofulvenallene 17, are explained in terms of two reaction paths, (a) a rearrangement to benzofulvenyl-7-carbene 13 and (b) a rearrangement to 1-naphthylcarbene 1. Moreover, 16 is also formed from 2-azulenylcarbene 30, thereby indicating the occurrence of a 2-azulenylcarbene-1-azulenylcarbene rearrangement. The reaction mechanisms are supported by density functional theory calculations at the B3LYP/6-31G** level, which indicate that all the rearrangements have activation barriers of <35 kcal/mol, thus making them readily achievable under FVP conditions.
通过下落固体快速真空热解（FS-FVP）方法，由5-(1-薁基)四唑和薁-1-甲醛对甲苯磺酰腙的钠盐生成了1-薁基卡宾18。主要产物环丁并[de]萘6、环戊并[cd]茚16和苯并富烯丙二烯17也由1-萘基卡宾和2-萘基卡宾生成，这些产物可通过两条反应路径来解释：(a) 重排为苯并富烯基-7-卡宾13；(b) 重排为1-萘基卡宾1。此外，2-薁基卡宾30也生成了16，从而表明发生了2-薁基卡宾-1-薁基卡宾重排。这些反应机理得到了B3LYP/6-31G**水平的密度泛函理论计算的支持，计算结果表明所有重排的活化能垒均<35 kcal/mol，因此在FVP条件下很容易实现。
