ChemInform Abstract: FLUORIDE‐INDUCED 1,2‐ELIMINATION OF O‐(TRIMETHYLSILYL)PHENYL TRIFLATE TO BENZYNE UNDER MILD CONDITIONS

Abstract

Das aus dem Silylether (I) zugängliche Triflat (II) wird durch die Fluoride (III) in Dehydrobenzol (IV) übergeführt, das mit Furan (V) zum Addukt (VI) und mit den Alkoholen (VII) zu den Phenolethern (VIII) weiterreagiert.

New Hindered Amide Base for Aryne Insertion into Si–P, Si–S, Si–N, and C–C Bonds

“…1 Several methods have been used for aryne generation (Scheme 1). 2 Pathway A involves lithium-halogen exchange followed by LiX elimina tion. This methodology is limited by alkyllithium reactivity that precludes use of many common functionalities.…”

“…Early investigations involved use of hydroxide, alkoxide, or amide (NaNH 2 ) bases which trapped the formed arynes. 2c,d Deprotonation of aryl fluorides with a BuLi/NaOtBu mixture or aryl chlorides with BuLi allowed reactions to proceed at low temperatures; however, this method for aryne generation is incompatible with many functional groups due to high reactivity of alkyllithium reagents. 2f,g Lithium amide bases such as LDA or lithium tetramethylpiperidide could be used at low temperatures as well.…”

“…2c,d Deprotonation of aryl fluorides with a BuLi/NaOtBu mixture or aryl chlorides with BuLi allowed reactions to proceed at low temperatures; however, this method for aryne generation is incompatible with many functional groups due to high reactivity of alkyllithium reagents. 2f,g Lithium amide bases such as LDA or lithium tetramethylpiperidide could be used at low temperatures as well. 2a,b,h,i However, the amide base reaction with generated aryne decreases product yields and necessitates use of excess aryne source, which may be problematic for complex molecule synthesis.…”

“…2f,g Lithium amide bases such as LDA or lithium tetramethylpiperidide could be used at low temperatures as well. 2a,b,h,i However, the amide base reaction with generated aryne decreases product yields and necessitates use of excess aryne source, which may be problematic for complex molecule synthesis. Pathway C, reaction of silyl aryl triflates or halides, is the mildest method for aryne generation.…”

O‐Arylation of Carboxylic Acids using (Phenyl)[2‐(trimethylsilyl)phenyl]iodonium Triflate as a Precursor of Arynes

“…Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions Arynes as useful reactive intermediates have received considerable attention in synthetic applications. [1] Before Himeshima et al first reported that 2-(trimethylsilyl)phenyl triflate 1 can generate arynes under mild conditions, [2] the general method for its generation was deprotonation from aromatic halogen compounds with a strong base, which is unfavorable to some substrates containing base-sensitive functional groups. Recently, using 1 as a precursor, reactions (especially a variety of nucleophile addition to arynes) have been studied for synthesizing polysubstituted arenes, which otherwise are difficult to prepare.…”