Department of Cardiovascular Research Laboratory, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China.
Shanghai Frontiers Science Center for Traditional Chinese Medicine Chemical Biology, Innovation Research Institute of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, China.
Org Lett. 2021 Oct 1;23(19):7336-7341. doi: 10.1021/acs.orglett.1c02421. Epub 2021 Sep 15.
Exploration of the diastereodivergent synthesis of spirocyclic oxindoles has been challenging. Herein we report asymmetric [3 + 2] annulations of isatin-derived Morita-Baylis-Hillman (MBH) carbonates and 5-alkenylthiazol-4(5)-ones. Interestingly, two different chiral catalysts, amide-phosphine and 4-dimethylaminopyridine (DMAP)-thiourea, could lead to two kinds of diastereomeric dispiro oxindoles with three contiguous stereogenic centers. The hexafluoroisopropanol (HFIP) additive plays a vital role in accelerating the reaction and tuning the diastereoselectivity. Moreover, both annulation adducts could be further converted to structurally diverse spirooxindoles.
手性螺环氧化吲哚的非对映选择性合成一直具有挑战性。在此，我们报道了基于色酮-4(5H)-噻唑-5-酮的 Morita-Baylis-Hillman (MBH) 碳酸酯的不对称[3 + 2]环加成反应。有趣的是，两种不同的手性催化剂，酰胺-膦和 4-二甲氨基吡啶 (DMAP)-硫脲，可以得到两种具有三个连续手性中心的非对映螺环氧化吲哚。六氟异丙醇 (HFIP) 添加剂在加速反应和调节非对映选择性方面起着至关重要的作用。此外，两个环加成产物都可以进一步转化为结构多样的螺环氧化吲哚。
