Synthesis of 4-allenyl and 4-proparyl-2-azetidinone via Zn-mediated Barbier-type reaction and Pt-catalyzed intramolecular amidation to carbapenem skeletons
摘要:
4-Propargyl-2-azetidinone and 4-allenyl-2-azetidinone derivatives can be facilely obtained from 4-acetoxy-2-azetidinone and propargyl bromides via zinc-mediated Barbier-type reaction. A new method has been developed to construct the carbapenem bicyclic nucleus by cyclization of 4-propargyl-2-azetidinone and 4-allenyl-2-azetidinone derivatives catalyzed by PtCl2. (c) 2007 Elsevier Ltd. All rights reserved.
The Indium-Mediated Selective Introduction of Allenyl and Propargyl Groups at the C4-Position of 2-Azetidinones and the AuCl3-Catalyzed Cyclization of 4-Allenyl-2-azetidinones
作者:Phil Ho Lee、Heechul Kim、Kooyeon Lee、Misook Kim、Kwanghyun Noh、Hyunseok Kim、Dong Seomoon
DOI:10.1002/anie.200462512
日期:2005.3.11
Synthesis of 3-Selena-1-dethiacephems and Selenazepines via Iodocyclization
作者:Dinesh R. Garud、Mamoru Koketsu
DOI:10.1021/ol801010y
日期:2008.8.7
A convenient approach to synthesize novel selenium-beta-lactams, 3-selena-1-dethiacephems and selenazepines, was accomplished via the regioselective iodocyclization reaction. The substituent of allenyl moieties dramatically influenced the regiochemical outcome in the iodocyclization of allene-selenourea derivatives.
Silver Mediated Cyclizations of 4-Allenyl-and 4-(2-Propynyl)azetidinones. A Stereoselective Synthesis of 3-Substituted Δ1-Carbapenems Via N-C3 Closure.
作者:J.Siva Prasad、Lanny S. Liebeskind
DOI:10.1016/s0040-4039(00)80467-0
日期:1988.1
First iodocyclization reaction of allene–thioureas: an efficient approach to bicyclic β-lactams
作者:Dinesh R. Garud、Amol R. Jadhav、Santosh V. Lahore、Nilesh M. Kahar、Rohini R. Joshi、Ramesh A. Joshi、Mamoru Koketsu
DOI:10.1016/j.tetlet.2014.09.004
日期:2014.10
The regioselective iodocyclization reaction of allene-thioureas is described, for the first time, for the synthesis of bicyclic beta-lactams. The substitution at the allenyl part heavily influenced the iodocyclization reaction. The iodocyclization reaction of the unsubstituted allene-thioureas afforded six-membered 3-thia-1-dethiacephems whereas, the substituted allene-thiourea afforded seven-membered thiazepines along with five-membered isopenams. (C) 2014 Elsevier Ltd. All rights reserved.
Silylstannylation of Allenes and Silylstannylation−Cyclization of Allenynes. Synthesis of Highly Functionalized Allylstannanes and Carbocyclic and Heterocyclic Compounds
作者:Ramaiah Kumareswaran、Seunghoon Shin、Isabelle Gallou、T. V. RajanBabu
DOI:10.1021/jo049010z
日期:2004.10.1
silicon−tin reagents to undergo the cyclization illustrate the scope and limitations of the reaction. Based on the isolation of intermediates, a mechanism for the formation of the cyclic compounds is proposed. Model transition states to explain the stereoselectivity in cyclization of substituted allenynes are provided. Further elaboration using the vinyltin and vinylsilane moieties should lead to highly functionalized