Unprecedented nucleophilic addition of organolithiums to aromatic aldehydes and ketones by complexation with aluminum tris(2,6-diphenylphenoxide).
Unprecedented nucleophilic addition of organolithiums to aromatic aldehydes and ketones by complexation with aluminum tris(2,6-diphenylphenoxide).
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DOI：
10.1021/ja00140a036
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发表时间：
1995-09
影响因子：
15
通讯作者：
K. Maruoka;Masahiro Ito;Hisashi Yamamoto
中科院分区：
文献类型：
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作者：
K. Maruoka;Masahiro Ito;Hisashi Yamamoto
尽管对缺电子芳烃（如硝基芳烃、芳基重氮化合物和恶唑啉）进行亲核加成的芳烃取代反应有多种方法，但对具有简单羰基和羧基官能团的芳核的亲核加成反应知之甚少，这些官能团作为吸电子基团具有弱的活化能力。在该领域的最新进展仅由富冈和古贺利用有机锂与空间位阻的2，6-二叔丁基-4-甲氧基苯基萘甲酸酯的共轭加成实现。3在本通讯中，我们描述了有机锂与简单芳族醛和酮的区域选择性共轭加成的第一个例子，该反应是通过与作为有效羰基稳定剂的三（2，6-二苯基苯酚）铝（ATPH）4· 5络合进行的（方案1）。反应性有机金属试剂通常以1，2方式加成到苯甲醛（1）或苯乙酮（2）上。例如，苯甲醛与t-BuLi在乙醚或THF中在-78 ℃下烷基化得到1，2-加合物2，2-二甲基-2-苯基-1-丙醇
Despite the availability of various procedures for arene substitu-tion via nucleophilic addition to electron-deficient arenes, such as nitroarenes, aryldiazonium compounds, and oxazolines, k· 2 little is known about nucleophilic addition to an aromatic nucleus with simple carbonyl and carboxyl functionalities which act as electron-withdrawing groups with weak activating capabilities. Recent progress in this field has been achieved only by Tomioka and Koga using the conjugate addition of organolithiums to sterically hindered 2, 6-di-ferf-butyl-4-methoxyphenyl naphthalenecarboxylates. 3 In this Communication, we describe the first example of the regioselective conjugateaddition of organolithi-ums to simple aromatic aldehydes and ketones by complexation with aluminum tris (2, 6-diphenylphenoxide)(ATPH) 4· 5 as an efficient carbonyl stabilizer (Scheme 1). Reactive organometallic reagents normally add to benzaldehyde (1) or acetophenone (2) in a 1, 2 fashion. For example, alkylation of benzaldehyde with f-BuLi in ether or THF at—78 C gives rise to the 1, 2-adduct 2, 2-dimethyl-2-phenyl-1-propanol