scholarly journals Efficient Tandem Addition/Cyclization for Access to 2,4-Diarylquinazolines via Catalytic Carbopalladation of Nitriles

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 463
Author(s):  
Julin Gong ◽  
Kun Hu ◽  
Yetong Zhang ◽  
Yinlin Shao ◽  
Tianxing Cheng ◽  
...  
Keyword(s):  
Intramolecular Cyclization ◽  
Nucleophilic Addition ◽  
Functional Group ◽  
Synthetic Pathway ◽  
Arylboronic Acids ◽  
Palladium Catalyzed ◽  
Plausible Mechanism

The first example of the palladium-catalyzed tandem addition/cyclization of 2-(benzylidenamino)benzonitriles with arylboronic acids has been developed. This transformation features good functional group tolerance and provides an alternative synthetic pathway to access 2,4-diarylquinazolines in moderate to good yields. A plausible mechanism for the formation of 2,4-diarylquinazolines involving sequential nucleophilic addition followed by an intramolecular cyclization is proposed.

Dual Nickel/Palladium-Catalyzed Reductive Cross-Coupling Reactions Between Two Phenol Derivatives

2020 ◽  
Author(s):  
Baojian Xiong ◽  
Yue Li ◽  
Yin Wei ◽  
Søren Kramer ◽  
Zhong Lian
Keyword(s):  
Functional Group ◽  
Low Cost ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Phenol Derivatives ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed ◽  
One Step ◽  
Aryl Tosylates ◽  
Low Sensitivity

Cross-coupling between substrates that can be easily derived from phenols is highly attractive due to the abundance and low cost of phenols. Here, we report a dual nickel/palladium-catalyzed reductive cross-coupling between aryl tosylates and aryl triflates; both substrates can be accessed in just one step from readily available phenols. The reaction has a broad functional group tolerance and substrate scope (>60 examples). Furthermore, it displays low sensitivity to steric effects demonstrated by the synthesis of a 2,2’disubstituted biaryl and a fully substituted aryl product. The widespread presence of phenols in natural products and pharmaceuticals allow for straightforward late-stage functionalization, illustrated with examples such as Ezetimibe and tyrosine. NMR spectroscopy and DFT calculations indicate that the nickel catalyst is responsible for activating the aryl triflate, while the palladium catalyst preferentially reacts with the aryl tosylate.

scholarly journals Facile assembly of 1,5-diazocan-2-ones via cyclization of tethered sulfonamides to cyclopropenes

RSC Advances ◽  
2020 ◽  
Vol 10 (72) ◽  
pp. 44183-44190
Author(s):  
Jonathon P. Matheny ◽  
Pavel M. Yamanushkin ◽  
Peter A. Petillo ◽  
Michael Rubin
Keyword(s):  
Nucleophilic Addition ◽  
Functional Group ◽  
Strain Release

The sulfonamide moiety was evaluated as an activating and stabilizing functional group in the metal templated strain release-driven intramolecular nucleophilic addition of amines to cyclopropenes to generate 1,5-diazocan-2-ones.

scholarly journals Isolation of a post-PKS C–C branching jadomycin from S. venezuelae ISP5230 in the presence of 8-aminooctanoic acid

2018 ◽  
Vol 96 (7) ◽  
pp. 760-764 ◽  
Author(s):  
Jeanna M. MacLeod ◽  
Stephanie M. Forget ◽  
Camilo F. Martinez-Farina ◽  
David L. Jakeman
Keyword(s):  
Natural Products ◽  
Amino Acid ◽  
Natural Product ◽  
Intramolecular Cyclization ◽  
Nucleophilic Addition ◽  
Culture Method ◽  
Amino Acid Supplementation ◽  
Acid Supplementation

The jadomycin family of natural products was first identified and characterized by Vining and co-workers at Dalhousie University in the 1990s. Herein, we report findings from a recently developed co-amino acid supplementation culture method with S. venezuelae ISP5230 using 8-aminooctanoic acid, where the major natural product was a jadomycin variant omitting an E-ring (1). These results reinforce that the 3a position is susceptible to nucleophilic addition by cellular metabolites in jadomycin biosynthesis when intramolecular cyclization is unfavorable. Further, the cytotoxicity data for several unsubstituted E-ring jadomycins are reported and discussed.

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