In(OTf)3-catalyzed tandem nucleophilic addition and cyclization of ortho-alkynylarylaldimines to 1,2-dihydroisoquinolines.
In(OTf)3-catalyzed tandem nucleophilic addition and cyclization of ortho-alkynylarylaldimines to 1,2-dihydroisoquinolines.
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DOI：
10.1002/anie.200600408
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发表时间：
2006-06
影响因子：
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通讯作者：
R. Yanada;Shingo Obika;Hideki Kono;Y. Takemoto
中科院分区：
文献类型：
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作者：
R. Yanada;Shingo Obika;Hideki Kono;Y. Takemoto
[1]它们作为基本反应的路易斯酸催化剂的潜力，如Diels-Alder，[2a，b]Friedel-Craft，[2c]Mukaiyama Aldol，[2d]和Sakurai-Hosomi烯丙基化反应，[2e，f]在过去的十年中得到了广泛的研究。[2]最近，某些铟(III)盐以及其他过渡金属化合物被发现具有π酸性，并通过与π电子配位来激活C？C多键。[3]几种InX3催化的芳烃的亲核加成反应，[4a，b]，1，13-二羰基化合物，[4c，d]和杂原子化合物，如苯胺[4e，f]和硫醇[4G]到三键。[4]催化双重活化，其中一个金属络合物在一次转化中表现出两种作用，从原子经济和机理的观点来看，在有机合成中具有重要的意义。[5]最近，Shibasaki和他的同事开发了一种有效的方法，通过在铟(III)催化剂上同时激活一个软亲核试剂和一个硬亲核试剂，催化醛和酮的烷基化反应。目前还没有关于InX3催化剂同时激活硬亲电和软亲电体的报道。在这种背景下，我们有兴趣开发InX3催化的环化反应，通过亚胺和C±C三键的串联亲核加成生成1，2-二氢异喹啉，[7]，这是已知的具有生物活性的天然产物的多种中间体。这种6-内环加成喹啉的反应已经通过几种过渡金属催化剂被开发出来。[3C，e-I]我们以前报道了光学活性的醛二胺与原位制备的烯丙基铟试剂的非对映选择性烯丙化反应[式(1)]，[8]，因此计划开发一系列
C= O and C= N bonds.[1] Their potential as Lewis acid catalysts for fundamental reactions, such as the Diels–Alder,[2a, b] Friedel–Crafts,[2c] Mukaiyama aldol,[2d] and Sakurai–Hosomi allylation reactions,[2e, f] has been extensively investigated over the last decade.[2] Recently, certain indium (iii) salts, as well as other transition-metal compounds, were found to have π acidity and to activate CÀC multiple bonds by coordination to π electrons.[3] Several InX3-catalyzed nucleophilic additions of arenes,[4a, b] 1, 3-dicarbonyl compounds,[4c, d] and heteroatomic compounds, such as anilines [4e, f] and thiols [4g] to triple bonds, have been reported.[4]Catalytic dual activation, in which a metal complex exhibits two roles in a single transformation, is of major interest in organic synthesis from the atom-economy and mechanistic points of view.[5] Recently, Shibasaki and coworkers developed an efficient method for catalytic alkynylation of aldehydes and ketones by using the dual activation of a soft nucleophile and a hard electrophile with an indium (iii) catalyst.[6] However, to the best of our knowledge, there have been no reports of dual activation of both hard and soft electrophiles by an InX3 catalyst. In this context, we are interested in developing InX3-catalyzed annulation reactions to form 1, 2-dihydroisoquinolines,[7] which are known to be versatile intermediates for biologically active natural products, through tandem nucleophilic additions to both imines and CÀC triple bonds. Such 6-endo-dig cyclizations into quinolines has already been developed by using several transition-metal catalysts.[3c, e–i] We previously reported the diastereoselective allylation of optically active aldimines with an allyl indium reagent prepared in situ [Eq.(1)],[8] and thus planned to develop a tandem