Chiral dipole-stabilized anions: experiment and theory in benzylic and allylic systems. Stereoselective deprotonations, pyramidal inversions, and stereoselective alkylations of lithiated (tetrahydroisoquinolyl)oxazolines
α-Amino nitrile 2a was conveniently prepared in two individual steps from chiral hexafluorophosphate salt isoquinolinium (−)-8b including anodic cyanation as an efficient means to activate the sp3 C1–H bond of the THIQ nucleus. The lithiation of 2a was carried out in THF at −80 °C in the presence of LDA to produce a stable α-amino carbanion which was condensed on a large variety of alkyl halides. The
Identification of an Imine Reductase for Asymmetric Reduction of Bulky Dihydroisoquinolines
作者:Hao Li、Ping Tian、Jian-He Xu、Gao-Wei Zheng
DOI:10.1021/acs.orglett.7b01274
日期:2017.6.16
developed by simply optimizing the amount of cosolvent, and up to 15 g L–1 1-Me DHIQ was converted completely without a feeding strategy. Furthermore, the reaction proceeded well for a panel of dihydroisoquinolines, affording the corresponding tetrahydroisoquinolines (mostly in S-configuration) in good yields (up to 81%) and with moderate to excellent enantioselectivities (up to 99% ee).
鉴定出一种新的来自烟粉虱(Stack Stackerbrandtia nassauensis)(Sn IR)的亚胺还原酶,与其他报道的亚胺还原酶相比,该酶对1-甲基-3,4-二氢异喹啉(1-Me DHIQ)的催化效率提高了25到1400倍。随后,通过简单地优化助溶剂的量,开发了一种有效的Sn IR催化工艺,无需进料策略即可完全转化多达15 g L –1 1-Me DHIQ。此外,对于一组二氢异喹啉,反应进行得很好,以高收率(高达81%)和中等至优异的对映选择性(高达99%ee)提供了相应的四氢异喹啉(大部分呈S-构型)。
One-Pot Chemoenzymatic Cascade for the Enantioselective C(1)-Allylation of Tetrahydroisoquinolines
作者:Jack J. Sangster、Rebecca E. Ruscoe、Sebastian C. Cosgrove、Juan Mangas-Sánchez、Nicholas J. Turner
DOI:10.1021/jacs.2c09176
日期:2023.3.1
enantioenriched C(1)-allylated tetrahydroisoquinolines. This transformation couples a monoamine oxidase (MAO-N)-catalyzed oxidation with a metal catalyzed allylboration, followed by a biocatalytic deracemization to afford allylic amine derivatives in both high yields and good to high enantiomeric excess. The cascade is operationally simple, with all components added at the start of the reaction and can
Chiral dipole-stabilized anions: experiment and theory in benzylic and allylic systems. Stereoselective deprotonations, pyramidal inversions, and stereoselective alkylations of lithiated (tetrahydroisoquinolyl)oxazolines
作者:Kathleen Rein、Marta Goicoechea-Pappas、Tarakeshwar V. Anklekar、Georgina C. Hart、Gregory A. Smith、Robert E. Gawley