Enantioselective addition of various aryllithiumreagents to aromatic imines was catalyzed (20 mol-%) by readily accessible 1,2-diamines to afford a wide range of protected diarylmethylamines in up to 94 % enantiomeric excess. Furthermore, the absolute configuration of these arylation products was determined by using X-ray crystallography.
各种芳基锂试剂与芳族亚胺的对映选择性加成反应 (20 mol-%) 由易于获得的 1,2-二胺催化,得到多种保护的二芳基甲基胺,对映体过量高达 94%。此外,这些芳基化产物的绝对构型是通过使用 X 射线晶体学确定的。
Diastereoselective Synthesis of <i>syn</i>-β-Lactams Using Rh-Catalyzed Reductive Mannich-Type Reaction of α,β-Unsaturated Esters
The combination of Et2Zn and RhCl(PPh3)3 led to the facile generation of a rhodium–hydride complex (Rh–H) that catalyzed the 1,4-reduction of α,β-unsaturatedesters. The resulting rhodium enolate performed as a Reformatsky-type reagent and reacted with various imines to give syn-β-lactams in good to excellent yields with high diastereoselectivity.
Et 2 Zn和RhCl(PPh 3)3的组合导致容易生成铑-氢化物络合物(Rh-H),该络合物催化α,β-不饱和酯的1,4-还原。所得的烯醇铑作为Reformatsky型试剂起作用,并与各种亚胺反应,以良好的非对映异构体收率以优异的产率得到合成的-β-内酰胺。
Synthesis and application of a new pseudo C2-symmetric tertiary diamine for the enantioselective addition of MeLi to aromatic imines
作者:Quentin Perron、Alexandre Alexakis
DOI:10.1016/j.tetasy.2007.10.018
日期:2007.10
A new tertiary pseudo C2-symmetric diamine derived from (1S,2S)-(+)-pseudoephedrine was synthesized and tested in the enantioselective addition of methyllithium on different aromatic imines. A comparative study with a similar C2-symmetric ligand derived from the cyclohexane diamine showed better reactivity and enantioselectivity up to 91%.
Asymmetric synthesis of β-lactams by chiral ester enolate - imine condensation
作者:Iwao Ojirna、Ivan I-Iabus
DOI:10.1016/s0040-4039(00)97603-2
日期:1990.1
Asymmetric cyclocondensation of N,N-bis(silyl)glycinates bearing chiral ester moieties with aldimines is found to proceed with extremely high enantioselectivity to give the corresponding chiral β-lactams in good to high yields. It is found that the E/Z-geometry of the chiral ester-enolate ts responsible for cis/trans stereochemistry of the β-lactam formed. Effects of various chiral auxiliaries in the
Enantioselective Generation of Adjacent Stereocenters in a Copper‐Catalyzed Three‐Component Coupling of Imines, Allenes, and Diboranes
作者:Kay Yeung、Rebecca E. Ruscoe、James Rae、Alexander P. Pulis、David J. Procter
DOI:10.1002/anie.201606710
日期:2016.9.19
enantio‐ and diastereoselective copper‐catalyzed three‐component coupling affords the first general synthesis of homoallylicamines bearing adjacent stereocenters from achiral starting materials. The method utilizes a commercially available NHC ligand and copper source, operates at ambient temperature, couples readily available simple imines, allenes, and diboranes, and yields high‐value homoallylic amines