CYCLOADDUCTS OF ARYNES WITH 1,3-BIS(TRIMETHYLSILYL)NAPHTHO[1,2-C]FURAN - FORMATION OF NOVEL POLYCYCLIC AROMATIC DERIVATIVES AND RELATED REACTIONS
CYCLOADDUCTS OF ARYNES WITH 1,3-BIS(TRIMETHYLSILYL)NAPHTHO[1,2-C]FURAN - FORMATION OF NOVEL POLYCYCLIC AROMATIC DERIVATIVES AND RELATED REACTIONS
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DOI：
10.1021/jo00366a015
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发表时间：
1986-08-08
影响因子：
3.6
通讯作者：
RICKBORN, B
中科院分区：
文献类型：
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作者：
POLLART, DJ;RICKBORN, B
最近开发的一种制备三甲基硅基化异苯并呋喃的方法以及这些材料在环加成反应中的应用已扩展到异萘并呋喃类似物。已分离出1，3-双（三甲基硅烷基）萘并[1，2-c]呋喃（7）;其与马来酸酐在室温下的反应是快速且容易可逆的，如由内到外环加合物的相互转化所示。7不能得到与2-丁烯基呋喃的环加合物，表明它的反应性低于母体萘并[1，2-c]呋喃。介绍了各种芳炔（苯炔、4-甲基苯炔、3，4-吡啶炔、9，10-菲咯啉、1，2-萘炔和2，3-萘炔）的原位生成和环加成反应。这三种不对称芳炔均生成环加合物的混合物，表明在与7的Diels-Alder反应中区域选择性可忽略不计;因此，尽管可能存在空间位阻，但与1，2-萘炔的反应得到二苯并[o，h]-和二苯并[o j]蒽衍生物的1：1混合物。相比之下，1-乙氧基-3-（三甲基甲硅烷基）萘并[I，2-c]呋喃（21）与1，2-萘乙炔的反应表现出适度的区域选择性，有利于二苯并[a，j]蒽衍生物的形成。介绍了环加成物的各种反应，最近发展的一种方法1可以将1，3-二氢-1-乙氧基异苯并呋喃一烧瓶转化为1，3-双（三甲基硅基）异苯并呋喃，然后与原位生成的芳炔进行环加成反应，得到新型多环化合物。本文将此方法推广到萘并[1，2-c]呋喃（苯并-[e]异苯并呋喃）体系，该体系已被证明可通过二烷基氨基锂诱导的1，4-消除反应来实现。我们感兴趣的是形成双（三甲基硅基）衍生物的可行性，其相对反应活性，与芳基的环加成反应是否会
A recentlydeveloped procedure for the preparation of trimethylsilylated isobenzofurans and the use of these materials in cycloaddition reactions has been extended to an isonaphthofuran analogue. The l, 3-bis (trimethylsilyl) naphtho [1, 2-c] furan (7) has been isolated; its reaction with maleic anhydride at room temperature is rapid and readily reversible as shown by endo to exo cycloadduct interconversion. The failure of 7 to give cycloadduct with 2-butenolide indicates that it is less reactive than the parent naphtho [1, 2-c] furan. In situ generation and cycloaddition reactions with various arynes (benzyne, 4-methylbenzyne, 3, 4-pyridyne, 9, 10-phenanthrolyne, 1, 2-naphthalyne, and 2, 3-naphthalyne) are described. The three unsymmetrical arynes all give mixturesof cycloadducts indicative of negligible regioselectivity in Diels-Alder reactions with 7; thus, in spite of possible steric hindrance the reaction with 1, 2-naphthalyne gives a 1: 1 mixture of dibenz [o, h]-and dibenz [o j] anthracene derivatives. In contrast, the reaction of l-ethoxy-3-(trimethylsilyl) naphtho [l, 2-c] furan (21) with 1, 2-naphthalyne exhibits modest regioselectivity, favoring the formation of the dibenz [a j] anthracene derivative. Various reactions of the cycloadducts are described.A recently developedprocedure1 allows the one-flask conversion of 1, 3-dihydro-l-ethoxyisobenzofuran to 1, 3-bis (trimethylsilyl) isobenzofuran, and subsequent cyclo-addition with in situ generated arynes, to afford novel polycyclic materials. This paperdescribes the extension of this methodology to the naphtho [l, 2-c] furan (benzo-[ejisobenzofuran) system, which has been shown2 to be accessible through lithium dialkylamide induced1, 4-elim-ination reactions. We were interested in the feasibility of forming the bis (trimethylsilyl) derivative, its relative re-activity, whether cycloaddition reactions with arynes would