Gold‐katalysierte 1,2‐Difunktionalisierung von Alkinen mit sichtbarem Licht ohne zusätzlichen Photosensibilisator

Gold(III) Meets Azulene: A Class of [(tBuC∧N∧C)AuIII(azulenyl)] Pincer Complexes

“…The azulenes were conveniently synthesized according to the reported dimerization of diaryl alkynes . The mercury-free preparation of [( t Bu C ∧ N ∧ C)­Au III Cl] was conducted by following the new protocol of the Hashmi group. − Scheme outlines the synthesis of the presented precursors and the corresponding [( t Bu C ∧ N ∧ C)­Au III azulenyl] complexes 3 , 5 , and 7 . A simple Sonogashira reaction with the TMS-protected alkyne provided the desired products in 65% yield.…”

Redox‐Neutral Arylations of Vinyl Cation Intermediates

“…These reactions lead to the formation of α‐aryl ketones or E ‐configured α‐aryl enones and enals at will, and show a tolerance for a wide range of functionality. The ortho ‐ or ortho/meta ‐substitution patterns on the aryl moiety, arising from [3,3]‐sigmatropic rearrangement, are unprecedented in the 1,2‐difunctionalization of alkynes and propargyl alcohols,– and offer handles for further elaboration by palladium‐catalyzed cross‐coupling and conjugate additions. The procedures detailed herein benefit from the use of highly stable and, in most cases, commercially available starting materials, as well as operational simplicity (atmospheric conditions, “wet” solvents, facile purification) and the atom‐economical nature of the reactions, including quantitative recovery of excess reagents.…”

Insights into the Mechanism of Gold(I) Oxidation with Aryldiazonium Salts

“…In 2016, the group of Hashmi described a1 ,2-difunctionalization of alkynes with aryldiazoniums alts to afford a-aryl ketones (Scheme 15 a). [41] In this work, they tried to use gold both as ac atalysta nd as ap hotosensitizer,i nspired by previous resultso ft he group and the work of Barriault andc oworkers, whichs howedt hat dimeric goldc omplexes can act as photosensitizers. [42] Curiously,t hey found that (4-CF 3 C 6 H 4 ) 3 PAuCl alone afforded the desired target molecules under blue LEDs irradiation, although the UV/Vis absorption spectrum of the gold complex showedavery weak absorption at 450 nm.…”