Albrecht Fabian, Sowada Oliver, Fistikci Meryem, Boysen Mike M K
Leibniz University of Hannover , Institute of Organic Chemistry, Schneiderberg 1B, D-30167 Hannover, Germany.
Org Lett. 2014 Oct 3;16(19):5212-5. doi: 10.1021/ol502630w. Epub 2014 Sep 25.
Rhodium(I)-catalyzed 1,4-addition of aryl and alkenylboronic acids to α,β-unsaturated carbonyl compounds is well established, but the transfer of heteroaryl residues in this reaction remains underdeveloped. We have studied heteroaryl MIDA and pinacol boronates as alternatives to the labile boronic acid counterparts. Under racemic conditions, 12 adducts with heteroaryl residues, among them unsubstituted 3- and 4-pyridinyl, 2-furanyl, thienyl, and pyrrolyl groups, were obtained in moderate to excellent yields. The enantioselective version of the reaction proved highly sensitive to the electronic character of the heteroaryl substituents, with boronates carrying electron-rich residues giving modest to high yields but consistently high enantiomeric excesses.
铑（I）催化芳基和烯基硼酸与α，β-不饱和羰基化合物的1,4-加成反应已得到充分确立，但该反应中杂芳基残基的转移仍未充分发展。我们研究了杂芳基MIDA硼酸酯和频哪醇硼酸酯作为不稳定硼酸对应物的替代物。在外消旋条件下，以中等至优异的产率获得了12种带有杂芳基残基的加合物，其中包括未取代的3-和4-吡啶基、2-呋喃基、噻吩基和吡咯基。该反应的对映选择性版本对杂芳基取代基的电子性质高度敏感，带有富电子残基的硼酸酯产率适中至高，但对映体过量始终很高。
