Integration of CO₂ Reduction with Subsequent Carbonylation: Towards Extending Chemical Utilization of CO₂

Abstract

Currently, it still remains a challenge to amplify the spectrum of chemical fixation of CO , although enormous progress has been achieved in this field. In view of the widespread applications of CO in a myriad of industrial carbonylation processes, an alternative strategy is proposed in which CO reduction to CO is combined with carbonylation with CO generated ex situ, which affords efficiently pharmaceutically and agrochemically attractive molecules. As such, CO in this study was efficiently reduced by triphenysilane using CsF to CO in a sealed two-chamber reactor. Subsequently, palladium-catalyzed aminocarbonylation, carbonylative Sonogashira coupling of aryl iodides, and rhodium(I)-mediated Pauson-Khand-type reaction proceeded smoothly to yield amides, alkynones, and bicyclic cyclopentenones, respectively. Furthermore, the formed alkynones can further be successfully converted to a series of heterocycles, for example, pyrazoles, 3a-hydroxyisoxazolo[3,2-a]isoindol-8-(3aH)-one derivatives and pyrimidines in moderate yields. The striking features of this protocol include operational simplicity, high efficiency, and relatively broad application scope, which represents an alternative avenue for CO transformation.

One‐Pot Palladium‐Catalyzed Carbonylative Sonogashira Coupling using Carbon Dioxide as Carbonyl Source

“…No better results were obtained when Et 2 SiH 2 , Ph 3 SiH and PhSi(OEt) 3 were examined (entries 2–4) in comparison with PhSiH 3 . Notably, in contrast to the previous report, [12g] the introduction of a fluoride inhibited the formation of the desired product, which might be due to the reason that fluoride was not conducive to the carbonylation reaction (entry 5). Moreover, we observed the amount of reductant had great impact on the reaction.…”

“…reported that silacarboxylic acids, which were produced from CO 2 and chlorosilane in the presence of lithium, could be utilized as efficient CO releasing molecules and further applied in the carbonylation process [12a–d] . The merges of fluoride‐catalyzed reduction of CO 2 by using stoichiometric amount of disilane and aminocarbonylations have also been reported respectively by the groups of Skrydstrup, Sundararaju and He [12e–g] . Additionally, Fleischer and coworkers proved that N ‐formyl saccharin derived from CO 2 could also be used as CO surrogate and applied in the Pd‐catalyzed alkoxycarbonylation of alkenes [12h] .…”

Cobalt‐Catalyzed Carbonylative Cyclization of Allyl Propargyl Ethers with Benzene‐1,3,5‐triyl Triformate as the CO Source

“…Also, raising or lowering the temperature hampered the reaction ( Table 1, entries [13][14]. Finally, a few other solvents including toluene, THF, and 1,4-dioxane were screened and the reaction gave inferior results ( Table 1, entries [15][16][17].…”

“…The presence of hydrosilane as the reductant was necessary (Scheme 1e). [17] Although these achievements have their own advantages, drawbacks including the use of expensive metal catalysts (Ru, Rh, Ir) or requires additional steps still remain.…”

Advance and Prospective on CO2 Activation and Transformation Strategy

“…将 CO 2 还原为 CO 再进行功能化反应可以极大地提 高 CO 2 的应用范围. 基于此, 我们 [19] [22] . 基于此, 我 们设计了 CO 2 与炔丙醇、亲核试剂的三组分串联反应, 为 CO 2 "变废为宝"的高值化利用提供新途径.…”