[2+2] Carbonylative cycloaddition catalyzed by palladium: stereoselective synthesis of β-lactams
作者:Luigino Troisi、Luisella De Vitis、Catia Granito、Tullio Pilati、Emanuela Pindinelli
DOI:10.1016/j.tet.2004.05.079
日期:2004.8
[2+2] Carbonylativecycloaddition of chiral imines to various allyl halides, under CO pressure, in the presence of Et3N, a catalytic amount of Pd(OAc)2 and PPh3 as ligand, are carried out. Separable diastereomeric mixtures of chiral alkenyl-β-lactams are isolated with good yields and high trans diastereoselections. Absolute configurations are assigned by X-ray measurements and 1H NMR spectroscopy.
[2 + 2]在Et 3 N存在下,在CO压力下,在CO压力下,将手性亚胺羰基化成环烷基加成各种烯丙基卤,催化量的Pd(OAc)2和PPh 3作为配体。手性烯基-β-内酰胺的可分离的非对映异构体混合物具有良好的收率和较高的反式非对映体选择性。通过X射线测量和1 H NMR光谱确定绝对构型。
Preparation of Stereodefined Homoallylic Amines from the Reductive Cross-Coupling of Allylic Alcohols with Imines
作者:Ming Z. Chen、Martin McLaughlin、Masayuki Takahashi、Michael A. Tarselli、Dexi Yang、Shuhei Umemura、Glenn C. Micalizio
DOI:10.1021/jo101535d
日期:2010.12.3
provide a means to translate the stereochemical information of the allylic alcohol to the homoallylic amine or to control diastereoselection in the coupling reactions of achiral allylic alcohols with chiralimines. Double asymmetric coupling reactions are also described that afford a unique means to control stereoselection in these complex convergent coupling processes. Finally, empirical models are
Stereoselective synthesis of heterosubstituted aziridines and their functionalization
作者:Luisella De Vitis、Saverio Florio、Catia Granito、Ludovico Ronzini、Luigino Troisi、Vito Capriati、Renzo Luisi、Tullio Pilati
DOI:10.1016/j.tet.2003.11.056
日期:2004.1
Lithiated (alpha-chloroalkyl)heterocycles, generated by deprotonation with LDA at -78 degreesC in THF, add to various enantiopure imines affording 'one pot' chiral heterosubstituted aziridines in a diastereoselective manner. Lithiated heterosubstituted aziridines, obtained by deprotonation of the corresponding aziridines with n-BuLi at -78 degreesC in THF, were trapped by electrophiles (D2O or CH3I) with high stereoselectivity. (C) 2003 Elsevier Ltd. All rights reserved.
Convergent Synthesis of Piperidines by the Union of Conjugated Alkynes with Imines: A Unique Regioselective Bond Construction for Heterocycle Synthesis
作者:Ming Z. Chen、Glenn C. Micalizio
DOI:10.1021/ol902169k
日期:2009.11.5
A two-step process is described for the union of aromatic imines, conjugated alkynes, and aldehydes that results in a stereoselective synthesis of highly substituted piperidines. This synthetic process has been made possible by defining a unique regioselective functionalization of conjugated alkynes that establishes a suitably functionalized substrate for subsequent heterocycle-forming cationic annulation. Given the flexibility of the coupling process, heterocycles can be accessed through a process that establishes up to four stereogenic centers and four fused rings.