Total Syntheses of (−) Epilupinine and (−)-Tashiromine Using Imino-Aldol Reactions
摘要:
Short routes to enantiomerically pure indolizidine and quinolizidine alkaloids have been developed using imino-aldol reactions of enolates derived from phenyl 5-chlorovalerate. High levels of syn selectivity (dr similar to 13-16:1) were obtained using lithium enolates of phenyl esters In combination with tert-butylsulfinyl imines. The imino-aldol adducts were deprotected and cyclized to afford (-)-epilupinine ((-)-2) and (-)-tashiromine ((-)-1) in two further steps.
O
<sub>2</sub>
‐Assisted Four‐Component Reaction of Vinyl Magnesium Bromide with Chiral
<i>N</i>
‐
<i>tert</i>
‐Butanesulfinyl Imines To Form
<i>syn</i>
‐1,3‐Amino Alcohols
作者:Runping Wang、Jingfan Luo、Chunmei Zheng、Hongyun Zhang、Lu Gao、Zhenlei Song
DOI:10.1002/anie.202109566
日期:2021.11.8
a new use: Vinyl magnesium bromide, a widely used Grignard reagent, can be oxygenated with O2 to give a magnesium enolate intermediate. This enables a four-component reaction that efficiently converts chiral N-tert-butanesulfinyl imine into a wide range of syn-1,3-amino alcohols in one step.
旧试剂新用途:乙烯基溴化镁是一种广泛使用的格氏试剂,可与 O 2氧化得到烯醇镁中间体。这使得四组分反应能够在一个步骤中有效地将手性N -叔丁烷亚磺酰基亚胺转化为范围广泛的顺-1,3- 氨基醇。
A general, enantioselective synthesis of 1-azabicyclo[m.n.0]alkane ring systems
作者:Timothy J. Senter、Michael L. Schulte、Leah C. Konkol、Tyler E. Wadzinski、Craig W. Lindsley
DOI:10.1016/j.tetlet.2013.01.041
日期:2013.3
In this Letter, we describe a novel approach for the general and enantioselectivesynthesis of a diverse array of small to large 1-azabicyclo[m.n.0]alkyl ringsystems with an embedded olefin handle for further functionalization. The stereochemistry is established via a highly diastereoselective indium-mediated allylation of an Ellman sulfinimine in greater than 9:1 dr, which is readily separable by