Brønsted Acid Catalyzed Peterson Olefinations

Abstract

A mild and facile Peterson olefination has been developed employing low catalyst loading of the Brønsted acid HNTf 2 . The reactions are typically performed at room temperature, with the reaction tolerant to a range of useful functionalities. Furthermore, we have extended this methodology to the synthesis of enynes.

Synthesis of Functionalized Isoindolinones via Calcium Catalyzed Generation and Trapping of N-Acyliminium Ions

“…Our group has a growing interest in developing methodology to catalytically generate reactive intermediates and in particular using calcium complexes to mediate these processes. , Calcium represents a relatively underexplored metal in catalysis; however, over the past decade, there has been an increase in interest in exploring the reactivity of calcium, which has resulted in a wealth of innovative uses for this abundant element. − We, and others, have recently reported the use of Ca­(NTf 2 ) 2 as an excellent catalyst to produce N -acyliminium ions from readily available 3-hydroxyisoindolinones. Due to the importance of these scaffolds in both total synthesis − and medicinal chemistry, we wanted to explore this reaction further.…”

“…Our group has a growing interest in developing methodology to catalytically generate reactive intermediates 36 and in particular using calcium complexes to mediate these processes. 37,38 Calcium represents a relatively underexplored metal in catalysis; 39 however, over the past decade, there has been an increase in interest in exploring the reactivity of calcium, which has resulted in a wealth of innovative uses for this abundant element.…”

Synergistic decarboxylation over Ce-doped Na/SiO2 facilitating functionalized monomer production from furfural for manufacturing polymers

“…For comparison, the reported approach involving the Grignard reaction was also carried out to obtain 2-vinylfuran using the typical procedures reported in the literature. 27,28 Herein, 5 ml furfural (60 mmol) in 60 ml Et 2 O and (trimethylsilyl)methylmagnesium chloride (1.3 M solution in THF, 50 ml, 1.08 equiv.) were used.…”

“…22–26 Current methods for 2-vinylfuran synthesis are dominated by Peterson olefination, in which renewable furfural and (trimethylsilyl)methylmagnesium chloride (TMSCH 2 MgCl) are used. 27,28 The Wittig reaction has also been applied for this route, which affords a 99% yield of 2-vinylfuran when a methyltriphenylphosphonium methylcarbonate salt ([Ph 3 PCH 3 ][CH 3 OCO 2 ]) was employed. 29,30 Unfortunately, a primary limitation of these methods is the low atom economy of the reaction, derived from the unavoidable formation of by-products ( e.g.…”

Aza-Peterson Olefinations: Rapid Synthesis of (E)-Alkenes

“…To date, there are no general set of conditions to access stereodefined 1,3-dienes via a Peterson olefination. Given our groups interest in expanding the utility of the Peterson olefination (Scheme 2c), 32 we wanted to carry out a two-step (indirect) procedure, to access these important structural motifs. β-Hydroxysilanes were prepared via addition of Grignard reagents, to carbonyl compounds, followed by treatment of the β-hydroxysilanes with catalytic Brønsted acids.…”