One-pot sustainable synthesis of tertiary alcohols by combining ruthenium-catalysed isomerisation of allylic alcohols and chemoselective addition of polar organometallic reagents in deep eutectic solvents

Abstract

Transition-metal complexes and polarised organometallic reagents play together in Deep Eutectic Solvents.

Eine wasserhaltige Organokaliumverbindung basierend auf Bis(4,6‐tert‐Butylbenzoxazol‐2‐yl)methanid und ihre unerwartete Hydrolysebeständigkeit

“…Die Ergebnisse ließen die Schlussfolgerung zu, dass der vorliegende Lithium/Bromid-Austausch am Aromaten mindestens genauso schnell, wenn nicht sogar schneller vonstattengeht als eine konkurrierende Zersetzungsreaktion zu BuT und LiOT. [12][13][14][15][16][17][18] Darüber hinaus haben DESs eine weitreichende Anwendung in Form effektiver Elektrolytlçsungen fürS olarzellen sowie in der Biokatalyse und als Reaktionsmedium photosynthetischer Reaktionszentren im Bereich der Energietechnologie gefunden. Im Gegensatz dazu führten Versuche ohne Wasser zur signifikanten Verringerung beider Werte.…”

NCN–Pincer–Pd Complex as Catalyst for the Hiyama Reaction in Biomass-Derived Solvents

“…Most of the components of DES are considered harmless and biodegradable, 22 which added to the fact that they are nonflammable, makes them a good choice as alternative reaction media for organic transformations. [23][24] Some approaches to the Hiyama coupling in neoteric solvents include the use of water as reaction medium, usually under reflux conditions, using phase transfer catalyst or with highly activated starting materials, such as diazonium salts. [25][26][27][28][29] Ionic liquids, which share some of the advantages of DES, but with the drawbacks of being highly toxic and economically expensive, have also been recently investigated as reaction medium.…”

The Future of Polar Organometallic Chemistry Written in Bio‐Based Solvents and Water

“…The desired alcohols 25 have been straightforwardly synthesized in up to 99 % yield without the need of isolation/purification of any intermediate, and in the absence of tedious/intricate compartmentalisation procedures. Remarkably, this tandem protocol can also successfully be performed using pure water as the reaction medium . The first cascade reactions interfacing biocatalysis with transition‐metal catalysis in DESs have also been recently published by the same authors …”

“…During the last years, a tremendous advance has been made in the field of transition‐metal‐catalysed organic reactions in DESs as environmentally friendly reaction media, with broad application in well‐established synthetic procedures ranging from Pd‐catalysed (Suzuki‐Miyaura) cross‐coupling processes and aminocarbonylation reactions to Cu‐catalysed click chemistry reactions (CuAAC), among others . Building on previous findings, Capriati, García‐Álvarez and co‐workers have successfully assembled the Ru‐catalysed redox isomerisation of allylic alcohols 23 with the chemoselective addition of organolithium reagents to the in situ formed ketones 24 en route to tertiary alcohols 25 in DESs (Scheme ) …”