Catalytic Intramolecular Hydroamination of Hindered Alkenes Using Organolanthanide Complexes
摘要:
The intramolecular hydroamination of hindered alkenes has been developed as a versatile route to heterocyclic systems. The current process utilizes the unhindered catalyst system [Cp(2)(TMS)LnMe](2) (Ln = Sm, Nd) to effect the cyclization of hindered amino olefins, providing products containing quaternary centers. The process tolerates a wide variety of substitution patterns, allowing the construction of monocyclic as well as fused and bridged bicyclic heterocycles. Two experimental procedures were employed in this study: one without solvent, minimizing waste streams, the other in deuterated solvents, allowing NMR monitoring of the reaction. The yield of each reaction was high, with NMR analysis of the reactions in progress showing clean conversion from starting material to a single product in most cases.
Reaction Control in Synthetic Organic Photochemistry: Switching between [5+2] and [2+2] Modes of Cycloaddition
作者:Claudio Roscini、Kara L. Cubbage、Malcolm Berry、Andrew J. Orr-Ewing、Kevin I. Booker-Milburn
DOI:10.1002/anie.200904059
日期:2009.11.2
Split personality: Reaction conditions that enable powerful control over the mode of photocycloaddition in maleimides have been developed. Direct irradiation favors the [5+2] mode whereas sensitized irradiation allows a complete switch to the [2+2] mode (see scheme; TBS=tert‐butyldimethylsilyl).
Mild Conditions for Pd-Catalyzed Carboamination of <i>N</i>-Protected Hex-4-enylamines and 1-, 3-, and 4-Substituted Pent-4-enylamines. Scope, Limitations, and Mechanism of Pyrrolidine Formation
作者:Myra Beaudoin Bertrand、Joshua D. Neukom、John P. Wolfe
DOI:10.1021/jo801631v
日期:2008.11.21
with aryl bromides leads to greatly increased tolerance of functional groups and alkene substitution. Substrates derived from (E)- or (Z)-hex-4-enylamines are stereospecifically converted to 2,1'-disubstituted pyrrolidine products that result from suprafacial addition of the nitrogen atom and the aryl group across the alkene. Transformations of 4-substituted pent-4-enylamine derivatives proceed in high
Catalytic Intramolecular Hydroamination of Hindered Alkenes Using Organolanthanide Complexes
作者:Gary A. Molander、Eric D. Dowdy
DOI:10.1021/jo981345r
日期:1998.11.1
The intramolecular hydroamination of hindered alkenes has been developed as a versatile route to heterocyclic systems. The current process utilizes the unhindered catalyst system [Cp(2)(TMS)LnMe](2) (Ln = Sm, Nd) to effect the cyclization of hindered amino olefins, providing products containing quaternary centers. The process tolerates a wide variety of substitution patterns, allowing the construction of monocyclic as well as fused and bridged bicyclic heterocycles. Two experimental procedures were employed in this study: one without solvent, minimizing waste streams, the other in deuterated solvents, allowing NMR monitoring of the reaction. The yield of each reaction was high, with NMR analysis of the reactions in progress showing clean conversion from starting material to a single product in most cases.