Key Laboratory of Drug-Targeting of Education Ministry and Department of Medicinal Chemistry, West China School of Pharmacy, ‡State Key Laboratory of Biotherapy, West China Hospital, Sichuan University , Chengdu 610041, P. R. China.
Org Lett. 2014 Feb 21;16(4):1084-7. doi: 10.1021/ol4036402. Epub 2014 Feb 5.
A [1,5]-anion relay has been achieved in 3,3-bis(silyl) benzyl enol ether. Deprotonation at the sterically more accessible benzyl position triggers an intramolecular proton transfer to generate the thermodynamically more stable 3,3-bis(silyl) allyloxy lithium. This endo-oriented allyl anion is stable at -78 °C and undergoes diastereoselective syn-addition at the γ-position with aldehydes and ketones to give monobenzyl-substituted 1,2-diols.
[1,5]-阴离子接力在 3,3-双(硅基)苄基烯醇醚中得以实现。在空间上更容易接近的苄基位置进行脱质子化，引发分子内质子转移，生成热力学上更稳定的 3,3-双(硅基)烯丙氧基锂。这种内向取向的烯丙基阴离子在-78°C 时稳定，并与醛酮发生立体选择性 syn-加成，在γ-位生成单苄基取代的 1,2-二醇。
