Thermolysis of a spiro-fused oxadiazoline: The carbonyl ylide-cyclic carbene-diradical sequence
Thermolysis of a spiro-fused oxadiazoline: The carbonyl ylide-cyclic carbene-diradical sequence
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螺稠合恶二唑啉的热解：羰基叶立德-环状卡宾-二自由基序列
DOI：
10.1139/v02-126
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
J. Warkentin
中科院分区：
文献类型：
--
作者：
N. Merkley;J. Warkentin
螺环稠合恶二唑啉1在苯中的热分解导致N2的损失，形成羰基叶立德中间体。大部分叶立德断裂成丙酮和4-苯基-1，3-二氧六环-2-亚基，其可以用叔丁醇捕获。在不存在捕获剂的情况下，卡宾的主要途径是断裂成二自由基，5-苯基-2-氧杂-1-氧代-1，5-戊二基。后者与α-苯基-γ-丁内酯偶联并脱羧得到环丙基苯。反应的其他产物是卡宾明显插入苯溶剂的C-H键和丙酮的C-H键的产物。这样的反应似乎是没有先例的替代，非卡宾机制提出。关键词：二氧杂卡宾，羰基叶立德，环丙基苯，双自由基，内酯，恶二唑啉。
Thermolysis of spiro-fused oxadiazoline 1 in benzene led to loss of N2 to form a carbonyl ylide intermediate. Most of the ylide fragmented to acetone and 4-phenyl-1,3-dioxane-2-ylidene, which could be trapped with tert-butyl alcohol. In the absence of the trapping agent, the major pathway followed by the carbene was fragmentation to a diradical, 5-phenyl-2-oxa-1-oxo-1,5-pentanediyl. The latter diradical coupled to α-phenyl-γ-butyrolactone and decarboxylated to afford cyclopropylbenzene. Other products from the reaction were those of apparent insertion of the carbene into a C-H bond of the benzene solvent and into a C-H bond of acetone. Such reactions appear to be without precedent alternative, non-carbene mechanisms are proposed. Key words: dioxacarbene, carbonyl ylide, cyclopropylbenzene, diradical, lactone, oxadiazoline.