Development of the Suzuki−Miyaura Cross-Coupling Reaction:  Use of Air-Stable Potassium Alkynyltrifluoroborates in Aryl Alkynylations

Abstract

The palladium-catalyzed cross-coupling reaction of potassium alkynyltrifluoroborates with aryl halides or triflates proceeds readily with moderate to excellent yields. The potassium alkynyltrifluoroborates are air- and moisture-stable crystalline solids that can be stored indefinitely, which will provide an advantage in applications to combinatorial chemistry. The alkynyl cross-coupling reaction can be effected using 9 mol % of PdCl2(dppf).CH2Cl2 as catalyst in THF or THF-H2O in the presence of Cs2CO3 as the inorganic base. A variety of functional groups are tolerated in both partners.

Kreuzkupplungen von Organoboranen: ein einfacher Weg zum Aufbau von C‐C‐Bindungen (Nobel‐Aufsatz)

“…(27)]. [39] Die Zukunft Die Suzuki-Reaktion ist noch immer in der Entwicklung begriffen, und speziell im letzten Jahrzehnt wurden viele neue trans-CH=CH-nBu 55…”

Photochemistry in synthesis: Where, when, and why

“…The two methods were compared, choosing in this case a more complex, and obviously more expensive, target molecule, the alkynybenzoxazole shown in Scheme 2. This can be prepared from the corresponding chloro (or bromo) benzoxazole either by Sonogashira coupling [23] or by irradiation [24].…”

A General Strategy Toward Aromatic 1,2‐Ambiphilic Synthons: Palladium‐Catalyzed ortho‐Halogenation of PyDipSi‐Arenes

“…First, treatment of 2i with HF at room temperature led to selective substitution of the pyridine group with fluoride, [13] thus providing fluorosilane 7 in excellent yield. Next, o-iodoaryl fluorosilane 7 was alkynylated with potassium phenylethynyltrifluoroborate under Suzuki reaction conditions [14] and produced 8 in 66% yield. Alternatively, alkynylated aryl silane 8 can be accessed from 2i through a sequence involving Sonogashira reaction [15] with phenylacetylene and subsequent substitution of the pyridine group with fluoride.…”