Cu(II)-catalyzed highly enantioselective intramolecular cyclization of N-alkenylureas was developed for the concise assembly of chiral vicinal diamino bicyclic heterocycles. Facile removal of carbonyl group of the carbamido moiety allowed for ready access to enantioenriched cyclic vicinal diamines.
I<sub>2</sub>-Mediated oxidative bicyclization of 4-pentenamines to prolinol carbamates with CO<sub>2</sub> incorporating oxyamination of the CC bond
作者:Sheng Wang、Xiaowei Zhang、Chengyao Cao、Chao Chen、Chanjuan Xi
DOI:10.1039/c7gc01992k
日期:——
oxyamination reaction of alkenes with ambient CO2 is reported. In the presence of I2 and DBU, CO2 is applied in situ as a protectinggroup to regulate the nucleophilicity of the aminogroup and facilitate the bicyclization of 4-pentenamines with high chemoselectivity. Moreover, this reaction provided a feasible approach to prepare prolinol carbamates with good tolerance of functional groups and high efficiency
Palladium(II)-Catalyzed Intramolecular Diamination of Unfunctionalized Alkenes
作者:Jan Streuff、Claas H. Hövelmann、Martin Nieger、Kilian Muñiz
DOI:10.1021/ja055190y
日期:2005.10.1
Intramolecular diamination reactions are described which yield cyclic ureas as direct products of an oxidative alkene transformation in the presence of palladium acetate and iodosobenzenediacetate as terminal oxidant. The reaction is truly catalytic in metal catalyst and represents the proof of principle for this elusive type of alkene oxidation.
Palladium- and Ruthenium-Catalyzed Cycloisomerization of Enynamides and Enynhydrazides: A Rapid Approach to Diverse Azacyclic Frameworks
作者:P. Ross Walker、Craig D. Campbell、Abid Suleman、Greg Carr、Edward A. Anderson
DOI:10.1002/anie.201304186
日期:2013.8.26
I want to ride my azacycle: The title reaction of enynamides affords a wide diversity of azacycles. The reactions are high‐yielding, highly stereoselective, and proceed rapidly under mild reaction conditions. Equivalent transformations using enynhydrazides offer new routes to pyrazole and indazole scaffolds. Boc=tert‐butoxycarbonyl, EWG=electron‐withdrawing group, Ns=4‐nitrobenzenesulfonyl, Ts=4‐toluenesulfonyl
Metalated Nitriles: Halogen−Metal Exchange with α-Halonitriles
作者:Fraser F. Fleming、Zhiyu Zhang、Paul Knochel
DOI:10.1021/ol036202s
日期:2004.2.1
[reaction: see text] Alpha-halonitriles react with organometallic reagents in a facile halogen-metal exchange. The halogen-metal exchange is extremely fast with Grignard and alkyllithium reagents, generating metalated nitriles in situ with aldehyde, ketone, acid chloride, and acylcyanide electrophiles. Sequential halogen-metal exchange and methylation of conformationally constrained nitriles is highly