The annulation of phthalides with α-alkyl/arylacrylates in the presence of LDA/LHMDS is shown to directly give alkyl/aryl-1-naphthols. The method involving a novel dealkoxycarbonylation obviates the regiochemical issues in the synthesis of polysubstituted naphthalenes, and it forms the key step in a three-step total synthesis of arnottin I, a naphthobenzopyranone natural product.
Quinine-derived thiourea promoted enantioselective Michael addition reactions of 3-substituted phthalides to maleimides
作者:Jie Wang、Xin Li、Jin-Pei Cheng
DOI:10.1007/s11426-018-9393-2
日期:2019.5
A highly diastereoselective and enantioselective Michael addition/desymmetrization reaction of maleimides with prochiral 3- substituted phthalides catalyzed by quinine-derived bifunctional thiourea was realized. A broad range of the 3,3′-disubstituted phthalides bearing vicinal quaternary-tertiary stereogenic centers were synthesized in moderate to good yields (up to 96%) with high diastereoselectivities
Total Synthesis of Neo-Tanshinlactones through a Cascade Benzannulation-Lactonization as the Key Step
作者:Ketaki Ghosh、Raju Karmakar、Dipakranjan Mal
DOI:10.1002/ejoc.201300102
日期:2013.7
The cascade annulation-lactonization of phthalides with α-carboxyfurylacrylates in the presence of lithium hexamethyldisilazide (LiHMDS) provides both convergent and semiconvergent regioselective syntheses of neo-tanshinlactones in moderate yields. This methodology also offers an avenue for the direct syntheses of hitherto unreported 6-alkoxycarbonyl-substituted neo-tanshinlactones and their heterocyclic
Direct asymmetric Mannich reaction of phthalides: facile access to chiral substituted isoquinolines and isoquinolinones
作者:Jie Luo、Haifei Wang、Fangrui Zhong、Jacek Kwiatkowski、Li-Wen Xu、Yixin Lu
DOI:10.1039/c2cc31439h
日期:——
The first Mannich reaction employing phthalides using a quinidine-based multifunctional catalyst has been developed. The reported method led to the synthesis of 3,3-disubstituted phthalide derivatives in excellent yields, with good diastereo- and enantioselectivities. Convenient synthesis of chiral isoquinolinones and isoquinolines has also been demonstrated.