Activation of β-diketones for CO₂capture and utilization

Abstract

Herein, we explore the use of β-diketones for CO2 fixation and utilization based on their dual Brønested acid/Lewis base character upon activation by 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and zinc bromide (ZnBr2), respectively....

Chemical and Redox Non-Innocence in Low‐Valent Molybdenum β-Diketonate Complexes: Novel Pathways for CO2 and CS2 Activation

“…The nucleophilic addition recognized upon reacting CS2 and CO2 on K[ tBu diket] -(see SI for details), as well as reported carboxylation reactions of (di-)ketones in the presence of strong bases (e.g. DBU), 77 suggests that the first step of the reaction to be redox neutral and involves the formation of a transient Mo(II) (dithio)carboxylated complex, tBu Mo(II)•CE2 (E = O, S), in the reaction mixture (Scheme 3). We propose that the less electron withdrawing nature of the formed dithiocarboxylate moiety relative to a carboxylate moiety accounts for the difference in reactivity between CO2 and CS2.…”

The Use of Sustainable Transition Metals for the Cycloaddition of Epoxides and CO2 under Mild Reaction Conditions

“…The latter CC products were characterized by 13 C NMR and ex situ ATR-FTIR spectroscopies, with a carbonate carbon chemical shift and vibrational wavenumber at 149.2, 149.6 ppm and 1716.6, 1720.2 cm À 1 , respectively (Figure S48-49 and 57-58; SI). Our results provide an alternative methodology for the synthesis of pinene carbonate (PiC), [43] which is usually obtained from diol carbonylation using urea [65] or diphenyl carbonate. [66] Moreover, we successfully synthesized limonene carbonate (LC) under milder conditions once compared with previous reports.…”

“…[41] The performance characteristics of the above-mentioned catalytic system and the use of a co-catalyst will be discussed in detail (vide infra). Recently, our group reported on catalysing the coupling reaction by using one pot, in situ generated zinc complexes bearing ascorbate [42] and several diketones [43] under 1 bar CO 2 and moderate temperatures without the need for extra additives. As a continuation of our group efforts in applying naturally occurring and synthetic materials for CO 2 capturing and utilization, [44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59] we report on the synthesis of zinc curcumin (Zn-Cur) complex to catalyze the cycloaddition reaction of CO 2 with several terminal and internal epoxides including pinene and limonene oxides under ambient conditions.…”

In situ activation of green sorbents for CO2 capture upon end group backbiting

“…31 Furthermore, they can also be synthesized using green carbonylating agents such as propylene carbonate, as innovated by our research group, 32 CO 2 , 33,34 or scCO 2 . 35 Our recent findings on bio-renewables/materials, [36][37][38][39] fine chemicals, 22,[40][41][42][43][44] and natural/synthetic polymeric materials [45][46][47][48][49][50] serving as scaffolds for CO 2 sequestration/utilization unveil a newly developed strategy that can develop mechanistic approaches for CO 2 capture. 51,52 Several research groups [53][54][55][56] have studied the thermolysis of urethane with its derivative, illustrated by three separate individual steps.…”