Chiral Aluminum Catalyst System for the Enantioselective Addition of Vinylaluminum Reagents to Aldehydes: Metal Controlled Reversal of Enantioselectivity
Chiral Aluminum Catalyst System for the Enantioselective Addition of Vinylaluminum Reagents to Aldehydes: Metal Controlled Reversal of Enantioselectivity
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DOI：
10.1002/adsc.201600594
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发表时间：
2016-11
影响因子：
5.4
通讯作者：
P. Adate;T. Matsunaga;H. Shin;T. Harada
中科院分区：
文献类型：
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作者：
P. Adate;T. Matsunaga;H. Shin;T. Harada
开发了一种手性铝催化体系，用于醛的不对称乙烯化反应。β，β-二取代(E)-乙烯基铝试剂，通过端炔与三甲基铝(Me_3Al)的碳铝化反应生成的区域和立体选择性地生成，在随后的低催化剂负载量(5摩尔%)下与醛的不对称加成反应中直接使用，不转金属化为乙烯基钛试剂。该反应得到了相应的富含对映体的仲烯丙醇，与由同一配体衍生的手性钛配合物催化的密切相关反应中观察到的选择性相反。
A chiral aluminum catalyst system has been developed for the enantioselective vinylation of aldehydes. β,β-Disubstituted (E)-vinylaluminum reagents, generated regio- and stereoselectively by the carboalumination of terminal alkynes with trimethylalumunim (Me3Al), were used straightforwardly without transmetalation to vinyltitanium reagents in the subsequent enantioselective addition to aldehydes with a DPP-H8-BINOL-derived chiral aluminum catalyst at low catalyst loading (5 mol%). The reaction afforded the corresponding enantiomerically enriched secondary allylic alcohols with a reversal of the selectivity observed in closely related reactions catalyzed by a chiral titanium complex derived from the same ligand.