53847-19-1Relevant academic research and scientific papers
Noncanonical cation-π cyclizations of alkylidene β-ketoesters: Synthesis of spiro-fused and bridged bicyclic ring systems
Parsons, Dylan E.,Frontier, Alison J.
, p. 2008 - 2012 (2019)
Three cation-π cyclization cascades initiated at alkylidene β-ketoesters bearing pendent alkenes are described. Depending upon the alkene substitution pattern and the reaction conditions employed, it is possible to achieve selective synthesis of the three different types of products, including 1-halo-3-carbomethoxycyclohexanes, spiro-fused tricyclic systems, and [4.3.1] bridged bicyclic ring systems. All three reactions begin with 6-endo addition of an olefin to the alkylidene β-ketoester electrophile, followed by one of three different cation capture events.
Iridium(I)-Catalyzed Intramolecular Hydrocarbonation of Alkenes: Efficient Access to Cyclic Systems Bearing Quaternary Stereocenters
Fernández, David F.,Gulías, Moisés,Mascare?as, José L.,López, Fernando
, p. 9541 - 9545 (2017/08/01)
A catalytic, versatile and atom-economical C?H functionalization process that provides a wide variety of cyclic systems featuring methyl-substituted quaternary stereocenters is described. The method relies on the use of a cationic IrI–bisphosph
Enantioselective Intramolecular Hydroacylation of Unactivated Alkenes: An NHC-Catalyzed Robust and Versatile Formation of Cyclic Chiral Ketones
Janssen-Müller, Daniel,Schedler, Michael,Fleige, Mirco,Daniliuc, Constantin G.,Glorius, Frank
supporting information, p. 12492 - 12496 (2015/10/12)
A highly enantioselective intramolecular N-heterocyclic carbene (NHC)-catalyzed hydroacylation reaction gives access to a range of cyclic ketones from unactivated olefin-substituted aldehydes (up to 99% ee). Remarkably, aliphatic aldehydes were also transformed efficiently in an NHC-catalyzed hydroacylation reaction for the first time. 100% Organic: A highly enantioselective N-heterocyclic carbene (NHC)-catalyzed intramolecular hydroacylation of aromatic and, more interestingly, aliphatic aldehydes with unactivated olefins offers access to a range of cyclic α-chiral ketones bearing quaternary centers. The reaction was found to be highly robust and proceeds with excellent yield in the presence of a diverse range of functional groups.
A synthesis of 6-azabicyclo[3.2.1]octanes. The role of N-substitution
Pulipaka, Aravinda B.,Bergmeier, Stephen C.
, p. 1462 - 1467 (2008/09/17)
(Chemical Equation Presented) The intramolecular cyclization reactions of aziridines with π-nucleophiles can be a useful route to a number of heterocyclic and carbocyclic ring systems. We were particularly interested in the use of this cyclization reaction for the synthesis of 6-azabicyclo[3.2.1] octanes. We report here the development of a new synthesis of the aziridine necessary for the aziridine-π-nucleophile cyclization. We also report on the cyclization of aziridines with three different substitutions on the aziridine nitrogen. We have found that N-diphenylphospinyl and N-H aziridines, while participating in the initial ring-opening reaction, do not lead to the desired bicyclic ring systems. In contrast, a nosyl group on the aziridine nitrogen leads efficiently to the bicyclic ring system and can be readily deprotected.
