Intermolecular Allene Functionalization by Silver-Nitrene Catalysis
作者:Manuel R. Rodríguez、María Besora、Francisco Molina、Feliu Maseras、M. Mar Díaz-Requejo、Pedro J. Pérez
DOI:10.1021/jacs.0c04395
日期:2020.7.29
Under silver catalysis conditions, using [Tp*,BrAg]2 as the catalyst precursor, allenes react with PhI=NTs in the first example of efficient metal-mediated intermolecular nitrenetransfer to such substrates. The nature of the substituent at the allene seems crucial for the reaction outcome since arylallenes are converted into azetidine derivatives whereas methylene aziridines are the products resulting
A radical based addition–elimination route for the preparation of indoles
作者:John A. Murphy、Karen A. Scott、Rhona S. Sinclair、Concepcion Gonzalez Martin、Alan R. Kennedy、Norman Lewis
DOI:10.1039/b002565h
日期:——
Indoles, including tricyclic derivatives, are produced by cyclisations of aryl radicals onto vinyl halides followed by elimination of halide radical and tautomerism of the resulting product; the aryl radicals are produced using âclean methodologyâ either by reaction of iodide ions with arenediazonium salts or by reaction of phosphorus-centred radicals with aryl iodides.
Rhodium‐Catalyzed Parallel Kinetic Resolution of Racemic Internal Allenes Towards Enantiopure Allylic 1,3‐Diketones
作者:Lukas J. Hilpert、Bernhard Breit
DOI:10.1002/anie.201903365
日期:2019.7.15
parallel kinetic resolution of racemic 1,3‐disubstituted allenes by means of a rhodium‐catalyzed addition to 1,3‐diketones furnishing enantiopure allylic 1,3‐diketones is described. Mechanistic experiments demonstrate that the different allene enantiomers react in parallel to either the diastereomeric E‐ or Z‐allylic 1,3‐diketones with the same absoluteconfiguration of the newly formed stereogenic
Palladium‐ and Rhodium‐Catalyzed Dynamic Kinetic Resolution of Racemic Internal Allenes Towards Chiral Pyrazoles
作者:Lukas J. Hilpert、Simon V. Sieger、Alexander M. Haydl、Bernhard Breit
DOI:10.1002/anie.201812984
日期:2019.3.11
resolution (DKR) of racemic allenes leading to N‐allylated pyrazoles is described. Such compounds are of enormous interest in medicinal chemistry as certified drugs and potential drug candidates. The new methods feature high chemo‐, regio‐ and enantioselectivities aside from displaying a broad substrate scope and functional group compatibility. A mechanistic rational accounting for allene racemization and trans‐alkene
Regioselective Radical Bromoallylation of Allenes Leading to 2-Bromo-Substituted 1,5-Dienes
作者:Takashi Kippo、Takahide Fukuyama、Ilhyong Ryu
DOI:10.1021/ol201395p
日期:2011.8.5
regioselective radical bromoallylation of allenes proceeded efficiently in the presence of AIBN as a radical initiator to give 2-bromo-substituted 1,5-dienes in excellent yields. The addition of a bromine radical took place regioselectively onto the central carbon of allenes generating a stable allyl radical, which underwent addition/β-fragmentation reactions with allylbromides. The products could be