An Efficient and General Method for Formylation of Aryl Bromides with CO₂ and Poly(methylhydrosiloxane)

Abstract

The formylation of aryl halides with CO2 to generate aryl aldehydes is challenging. Herein, we report a novel synthesis of aryl aldehydes by formylation of aryl bromides with CO2 and a waste silane, poly(methylhydrosiloxane) (PMHS). It has been discovered that a simple combination of 1,3-bis(diphenyphosphino)propane (DPPP)-chelated Pd catalyst, Pd(DPPP)Cl2 , with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) is able to effectively catalyze the reaction, leading to aryl aldehydes in moderate to excellent yields, and without any by-products in most cases. Moreover, this route could be extended to the formylation of aryl iodides with high efficiency. This approach is simple, less costly, and environmentally friendly, and also widens the applications of CO2 to form value-added chemicals by the construction of new C-C bonds.

Supported Porous Nanomaterials as Efficient Heterogeneous Catalysts for CO2 Fixation Reactions

“…Here methyldiphenylsilane act as a strong reducing agent to form the benzyl alcohols as the end product in one step. However, a chelated Pd catalyst in the presence of poly(methylhydrosiloxane) (PMHS) and CO 2 resulted in the formylation of aryl bromides/iodides to their respective aldehydes in very high yields . These reactions widen the scope of CO 2 utilization for the synthesis of value‐added fine chemicals through the construction of new C−C bonds.…”

“…However, ac helated Pd catalyst in the presenceo fp oly(methylhydrosiloxane) (PMHS) and CO 2 resulted in the formylation of aryl bromides/iodides to their respective aldehydesi nv ery high yields. [84] These reactions widen the scope of CO 2 utilization for the synthesis of value-added fine chemicals through the construction of new CÀCb onds. In Figure 2w eh ave summarized the CO 2 fixation pathways for the synthesis of value-added aromatic alcohols, aldehydes, and acids directly from aryl halides over different Pd and Ni catalysts.…”

“…For the fixation of CO 2 into aryl halidest og ive aryl aldehydes over supported Pd catalysts, the 1,8-diazabicy-clo[5.4.0]undec-7-ene (DBU) molecule acts as ar eactive base in the presenceo ft he reducing agentp oly(methylhydrosiloxane) (PMHS). [202] Here PMHS reacts with CO 2 under ambient pressure to form silyl formate.Apart from base, DBU can act as reducing agent andi tc an help in reducing Pd II to ar eactive catalytic Pd 0 site so that the reaction can propagate smoothly.P d 0 could activate the CÀXb ond of the aryl halides( X= halides) to form an organopalladium complex in the presence of DBU base. This subsequently reacts with silyl formate to form aryl aldehydes as the sole products in this chemical fixation of CO 2 to aryl halides.…”

Rhodium-catalyzed reductive carbonylation of aryl iodides to arylaldehydes with syngas

“…Aromatic aldehydes are highly valuable organic compounds that are widely employed as indispensable building blocks in numerous areas of chemistry, especially for the preparation of biologically active molecules or their intermediates [28,29]. Generally, aromatic aldehydes are synthesized by Reimer-Tiemann, Gattermann-Koch, Vielsmeier-Haag, or Duff reactions and so forth.…”

An Experimental and Theoretical Study on the Unexpected Catalytic Activity of Triethanolamine for the Carboxylative Cyclization of Propargylic Amines with CO2

“…[1][2][3] In fact, CO 2 is usually considered as au biquitous, nontoxic,a nd renewable carbon resource, and can replace commonlyu sed toxic C1 buildingb locks. [4] Thus, fixation and conversion of CO 2 holds great promise for the recycling of CO 2 into value-addedp roducts.A tp resent,m any useful organic chemicals that are currently derived fromf ossil fuel-based resourcesh ave been produced by using CO 2 as af eed stock, such as alcohols, [5] cyclic carbonates, [6,7] formamide, [8] and carboxylic acidd erivatives. [9,10] However,o nly as mall proportion of the total abundance of CO 2 is currently being consumedi n industry because to establish ecological and economical CO 2 conversion processes is still ag reat challenge.…”