Ruthenium-Catalyzed Conjugation of Phenyl and Pyridyl Bioisosteres to Azines/Azoles via Dearomative Addition-Hydrogen
Yhin Sarah Teoh1, Seoyoung Lee1, Peyton W Meares1
1Department of Chemistry, University of Texas at Austin, Austin, Texas78712, United States.
None:
Using the inexpensive, air-stable ruthenium catalyst derived from RuHCl(CO)(PPh3)3 and the achiral ligands Cy-BIPHEP or dCypb, acetylenic bicyclooctyl, azabicycloheptyl, adamantyl, bicyclopentyl and azabicyclooctyl bioisosteres 2a-2f are conjugated to diverse azines and azoles 1a-1t via Csp2-Csp3 bond formation. Using chiral ruthenium catalysts modified by (S)-Cy-SEGPHOS or (R)-Cy-BINAP, high levels of enantioselectivity are obtained in reactions of azines. Late-stage C-H functionalization of the B(Epin) derivative of bortezomib (Velcade) and studies corroborating the reaction mechanism are described.
Related Concept Videos
Aryldiazonium Salts to Azo Dyes: Diazo Coupling
Preparation of 1° Amines: Azide Synthesis
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo, or cyano...
Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
Nucleophilic Aromatic Substitution: Elimination–Addition
Diazonium Group Substitution: –OH and –H


