The Stereoselective Synthesis of Alkenyl-β-lactams by Palladium-Catalyzed [2+2] Carbonylative Cycloaddition
作者:Luigino Troisi、Luisella De Vitis、Catia Granito、Erbana Epifani
DOI:10.1002/ejoc.200300667
日期:2004.3
Allyl halides of different structures, under CO pressure, in the presence of Et3N, a catalytic amount of Pd(OAc)2, and triphenylphosphane as ligand, undergo a [2+2] cycloaddition reaction with various imines. The reaction is highly regio- and stereoselective: β-lactams are formed in good yields and with trans diastereoselectivity in both the β-lactam ring and the vinylic moiety. New and important information
Pd-Catalyzed Carbonylation of Diazo Compounds at Atmospheric Pressure: A Catalytic Approach to Ketenes
作者:Zhenhua Zhang、Yiyang Liu、Lin Ling、Yuxue Li、Yian Dong、Mingxing Gong、Xiaokun Zhao、Yan Zhang、Jianbo Wang
DOI:10.1021/ja107351d
日期:2011.3.30
and affects the diastereoselectivity of the β-lactam products by assisting isomerization of the addition intermediate. On the other hand, the acylketenes generatedfrom the Pd-catalyzed carbonylation of α-diazoketones react with imines in a formal [4 + 2] cycloaddition manner to afford 1,3-dioxin-4-one derivatives. This straightforward carbonylation provides a new approach toward highly efficient catalytic
Stereoselective synthesis of trans β-lactams via palladium/N-heterocyclic carbene-catalyzed carbonylative [2+2] cycloaddition
作者:Pan Xie、Bo Qian、Hanmin Huang、Chungu Xia
DOI:10.1016/j.tetlet.2012.01.073
日期:2012.3
The carbonylative [2+2] cycloaddition of benzyl chlorides and allyl derivatives with imines and CO for synthesis of β-lactam is effectively catalyzed by palladium/N-heterocyclic carbene complex. The desired β-lactam could be obtained in good to excellent yields (61–96%) with excellent regioselectivities (trans/cis > 95:5) and chiral lactams could be obtained with moderate diastereoselectivities. The