(tmp)₂Zn⋅2 MgCl₂⋅2 LiCl: A Chemoselective Base for the Directed Zincation of Sensitive Arenes and Heteroarenes

Abstract

Positive zincing: A wide range of polyfunctional aryl and heteroaryl zinc reagents were efficiently prepared in THF by direct zincation using (tmp)2Zn⋅2 MgCl2⋅2 LiCl (1), an exceptionally active base. Ester and cyano functions as well as aldehydes and nitro groups are tolerated. dba=dibenzylideneacetone, tmp=2,2,6,6‐tetramethylpiperidide.

Catalytic methods of creation and functionalization of the coumarin skeleton

“…In the studies of Knochel [56] and Kim [57] it was established that coumarin and its 4-bromo derivative are effectively metallated at positions 3 and 4 respectively. The organozinc compounds obtained in situ were capable of entering into the Negishi catalytic reaction with aryl and hetaryl halides and acid chlorides of aromatic carboxylic acids.…”

Catalyst Activation, Deactivation, and Degradation in Palladium‐Mediated Negishi Cross‐Coupling Reactions

“…The popularity of organozinc halides results from their high reactivity combined with an excellent functional-group tolerance and easy accessibility. [9][10][11] …”

Thiosulfonates as Emerging Reactants: Synthesis and Applications

“…These authors also employed this efficient strategy for the sulfenylation of haloheteroarenes or heteroarenes involving halogen–metal exchange or direct(ed) metallation, respectively (Scheme ). This has been illustrated on 5‐iodouracil ( 196 ) (Scheme , route 1), 2,5‐dichlorothiophene ( 199 ) (route 2) and 2‐phenyl‐1,3,4‐oxadiazole ( 203 ) (route 3) . The Maes group used S ‐methyl methanethiosulfonate ( 9 ) as an electrophile to quench magnesiated pyridazin‐3(2 H )‐ones ( 206 ) (routes 4 and 5) .…”