Enantiomerically Pure N Chirally Substituted 1,3-Benzazaphospholes: Synthesis, Reactivity toward tBuLi, and Conversion to Functionalized Benzazaphospholes and Catalytically Useful Dihydrobenzazaphospholes
Enantiomerically Pure N Chirally Substituted 1,3-Benzazaphospholes: Synthesis, Reactivity toward tBuLi, and Conversion to Functionalized Benzazaphospholes and Catalytically Useful Dihydrobenzazaphospholes
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DOI：
10.1021/om401184n
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发表时间：
2014-02-10
期刊：
影响因子：
2.8
通讯作者：
Heinicke, Joachim W.
中科院分区：
文献类型：
--
作者：
Ghalib, Mohammed;Jones, Peter G.;Heinicke, Joachim W.
手性邻溴苯胺1a-c与相应的邻膦酰苯胺2a-c的催化C-P偶联，还原为膦3a-c，最后酸催化环化缩合代表了获得标题化合物4-c的方便途径。4a、B与tBuLi的反应允许溶剂依赖性的定向锂化，在茴香基取代伴随着MeO-基团的o-位的部分额外锂化的情况下，导致具有P= CLi-NR亚结构（在Et 2 O/KOtBu中）的2-锂基苯并氮杂磷杂环戊二烯，或者导致区域特异性的“正常”加成，形成-P-（tBu）-CHLi-NR-物质。用ClSiMe 3、CO2或MeOH捕集它们，分别得到相应的取代产物7 B、8 B、10 B、11 a、B和12 a、B。12 a，B，含有P-C-COOH结构单元，与Ni（COD）（2）在THF中形成非常有效的乙烯齐聚催化剂，对线性α-烯烃具有高选择性。产物的结构解析基于1-（1 S）-茴香乙基化合物3b和4 b的结论性溶液NMR数据和晶体结构分析。
Catalytic C-P coupling of chiral o-bromoanilines 1a-c to the corresponding o-phosphonoanilines 2a-c, reduction to the phosphines 3a-c, and final acid-catalyzed cyclocondensation represents a convenient access to the title compounds 4-c. Reaction of 4a,b with tBuLi allows solvent-dependent directed lithiation leading either to 2-lithiobenzazaphospholes with a P=CLi NR substructure (in Et2O/KOtBu), in the case of anisyl substitution accompanied by partial additional lithiation in o-position of the MeO-group, or to regiospecific "normal" addition with formation of -P-(tBu)-CHLi-NR- species. These were trapped by ClSiMe3, CO2, or MeOH to give the corresponding substitution products 7b, 8b, 10b, 11a,b and 12a,b, respectively. 12a,b, containing the P-C-COOH structural unit, forms with Ni(COD)(2) in THF very efficient ethylene oligomerization catalysts With high selectivity for linear alpha-olefins. The structure elucidation of the products is based on conclusive solution NMR data and crystal structure analyses of the 1-(1S)-anisylethyl compounds 3b and 4b.