Reduction of Cyclic and Linear Organic Carbonates Using a Readily Available Magnesium Catalyst

Abstract

Efficient reduction of cyclic and linear organic carbonates catalyzed by a readily available earth alkaline catalyst has been achieved. The described homogenous reaction based on a ligand-free magnesium catalyst provides an indirect route for the conversion of CO 2 into valuable alcohols. The reaction proceeds with high yields under mild reaction conditions, with low catalyst loading and short reaction times, and shows a broad applicability toward various linear and cyclic carbonates. Additionally, it can be applied for the depolymerization of polycarbonates.

Hydroboration of Nitriles, Esters, and Carbonates Catalyzed by Simple Earth‐Abundant Metal Triflate Salts

“…1 H NMR (400 MHz, C 6 D 6 ): δ (ppm) 4.45–4.37 (m, 1H, −OC H ), 3.78 (d, J =4.1 Hz, 2H, OC H 2 ), 3.47 (s, 3H, −OC H 3 ), 1.08 (s, 24H, C(C H 3 ) 2 ), 1.04 (s, 12H, −C(C H 3 ) 2 for MeOBpin),1.03–1.00 (m, 3H, −CHC H 3 ). Spectroscopic data are in agreement with those previously reported [15a] …”

“…1 H NMR (400 MHz, C 6 D 6 ): δ (ppm) 7.27 (d, J =7.0 Hz, 2H, Ar− H), 7.18‐7.11 (m, 4H, Ar− H (for both products) 7.10–7.03 (m, 3H, Ar− H (for both products)), 6.85 (t, J =6.1 Hz, 1H, Ar− H), 4.90 (s, 2H, −OC H 2 ), 3.48 (s, 3H, −OC H 3 ), 1.05 (s, 36H, −C(C H 3 ) 2 ); for three products). Spectroscopic data are in agreement with those previously reported [15a] …”

“…To further demonstrate the applicability of the herein reported methodology, we also investigated the hydroboration of carbonates and esters. Only in the past three years, a few earth‐abundant metal complexes have been reported that facilitate the hydroboration of (carbonate) esters [15a,24–25,26] . To our delight, initial studies showed that almost all screened metal(II) triflate salts were able to facilitate the borylation of ethylene carbonate with near quantitative conversion (Figure 1B, Table S2).…”

“…The hydroboration of carbonates or esters, on the other hand, has less frequently been explored. Only a few examples have been reported with magnesium‐based catalysts, [15a,24] while using other earth‐abundant metal based catalysts is scarce [25] . To illustrate, just recently Leitner and co‐workers reported the first manganese catalyst for the hydroboration of challenging carbonyl functionalities such as carbonates and carbon dioxide [26] .…”

Hydrosilylation and hydroboration in a sustainable manner: from Earth-abundant catalysts to catalyst-free solutions

“…The group of Rueping reported a series of examples that involve hydroboration of ketones, carbonates, and alkynes (Scheme 21). [130][131][132][133] In these processes, a commercially available, non-toxic, and quite inexpensive di-n-butylmagnesium solution has been applied as the catalyst. An enantioselective version provides products with excellent yields (up to 99%) and enantioselectivities (er up to 99 : 1).…”