A Powerful Aluminum Catalyst for the Synthesis of Highly Functional Organic Carbonates

Whiteoak, Christopher J.; Kielland, Nicola; Laserna, Víctor; Escudero‐Adán, Eduardo C.; Martín, Eddy; Kleij, Arjan W.

doi:10.1021/ja311053h

Cited by 451 publications

(234 citation statements)

References 45 publications

Supporting

Mentioning

230

Contrasting

Order By: Relevance

“…In fact, the chelating mode between transition metal centres and CO 2 has been investigated intensively via stoichiometric experimental studies 46,47 . and 1 bar CO 2 using bimetallic Al III -salen complexes. More recently, the Kleij group 18 presented an easily accessible amino triphenolate complex based on Al III metal centre. This complex is demonstrated to be a highly active and versatile catalyst for organic carbonate formation.…”

Section: Box 1 | Coordination Modes Of Co 2 With Transition Metalsmentioning

confidence: 99%

Using carbon dioxide as a building block in organic synthesis

et al. 2015

View full text Add to dashboard Cite

Carbon dioxide exits in the atmosphere and is produced by the combustion of fossil fuels, the fermentation of sugars and the respiration of all living organisms. An active goal in organic synthesis is to take this carbon-trapped in a waste product-and re-use it to build useful chemicals. Recent advances in organometallic chemistry and catalysis provide effective means for the chemical transformation of CO 2 and its incorporation into synthetic organic molecules under mild conditions. Such a use of carbon dioxide as a renewable one-carbon (C1) building block in organic synthesis could contribute to a more sustainable use of resources.A more sensible resource management is the prerequisite for the sustainable development of future generations. However, when dealing with the feedstock of the chemical industry, the level of sustainability is still far from satisfactory. Until now, the vast majority of carbon resources are based on crude oil, natural gas and coal. In addition to biomass, CO 2 offers the possibility to create a renewable carbon economy. Since pre-industrial times, the amount of CO 2 has steadily increased and nowadays CO 2 is a component of greenhouse gases, which are primarily responsible for the rise in atmospheric temperature and probably abnormal changes in the global climate. This increase in CO 2 concentration is largely due to the combustion of fossil fuels, which are required to meet the world's energy demand 1 . Obviously, there is an urgent need to control CO 2 emissions and develop efficient carbon capture systems. Although the extensive use of carbon dioxide for chemical production cannot solve this problem alone, CO 2 is a useful one-carbon (C1) building block in organic synthesis due to its abundance, availability, nontoxicity and recyclability. As a result, valorization of CO 2 is currently receiving considerable and ever increasing attention by the scientific community 2-4 . However, activation and utilization of CO 2 is still problematic due to the fact that it is the most oxidized form of carbon, which is also thermodynamically stable and/or kinetically inert in certain desired transformations. Consequently, most of the known studies used highly reactive substrates and/or severe reaction conditions to activate CO 2 , limiting the application of such methods. In particular, the catalytic coupling of CO 2 with energy-rich substrates, such as epoxides and aziridines, to generate polycarbonates/polycarbamates and/or cyclic carbonates/carbamates has drawn significant attention over the past decades. To create C-C bonds with CO 2 , the use of carbon nucleophiles is specifically limited to strong nucleophilic organolithiums and Grignard reagents, as well as phenolates.

show abstract

Section: Box 1 | Coordination Modes Of Co 2 With Transition Metalsmentioning

confidence: 99%

Using carbon dioxide as a building block in organic synthesis

et al. 2015

View full text Add to dashboard Cite

show abstract

“…North (TOF = 15000 h -1 ), employed using here TBAI as the nucleophilic co-catalyst. 42 Porphyrin-based catalysts are another class of powerful catalytic systems towards CO 2 coupling with oxiranes. These catalysts are characterized by a planar geometry, which is beneficial for the coordination of terminal epoxides.…”

Section: Development Of Improved Reactivity In Coc Synthesismentioning

confidence: 99%

“…Most internal epoxides were quantitatively converted to the corresponding COCs at low catalyst loadings, although higher reaction temperatures were required to achieve quantitative conversions (4 examples, yields: 55-98 %, 4d = TBAB = 0.5 mol%, T = 90 ºC, p(CO 2 ) = 1.0 MPa, t = 42 h). 42 Nevertheless, this catalytic system is not only one of the most active reported to date, but also one of the most versatile in terms of substrate scope.…”

Section: Conversion Of Internal Epoxides and Oxetanesmentioning

confidence: 99%

“…The 3,3´-dimethyl substituted oxetane was converted into its COC using Al(aminotriphenolate) complex 4d/TBAB as binary catalyst, affording the targeted product with moderate selectivity (54%) and low yield (26%; Entry 2, Table 3). 42 Alternatively, the use of 3-benzyloxymethyl-3-methyloxetane catalyzed by Cr(salen) complex 18b and TBAN 3 resulted in the preferred formation of the polycarbonate species (Entry 7, Table 3). This behavior has been ascribed to an increased steric hindrance of the substituents at 3-position.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Recent Advances in the Catalytic Preparation of Cyclic Organic Carbonates

2015

Self Cite

View full text Add to dashboard Cite

ABSTRACT:The catalytic formation of cyclic organic carbonates (COCs) using carbon dioxide (CO 2 ) as a renewable carbon feed stock is a highly vibrant area of research with an increasing amount of researchers focusing on this thematic investigation. These organic carbonates are highly useful building blocks and nontoxic reagents, and are most commonly derived from CO 2 coupling reactions with oxirane and di-alcohol precursors using homogeneous catalysis methodologies. The activation of suitable reaction partners using catalysis as a key technology is a requisite for efficient CO 2 conversion as its high kinetic stability poses a barrier to access functional organic molecules with added value in both academic and industrial laboratories. Though this area of science has been flourishing for at least a decade, in the last 2−3 years significant advancements have been made to address the general reactivity and selectivity issues that are associated with the formation of COCs. Here we present a concise overview of these activities with a primary focus to highlight the most important progress made and the opportunities that catalysis can bring about when the synthesis of these intermediates is optimized to a higher level of sophistication. The attention will be limited to those cases where homogeneous metal-containing systems have been employed as they possess the highest potential for directed organic synthesis using CO 2 as molecular building block. This review discusses examples of exceptional reactivity and selectivity taking into account the challenging nature of the substrates that were involved, and mechanistic understanding guiding the optimization of these protocols is also highlighted.

show abstract

“…[9] The importance of this catalytic transformation has been highlighted recently by Kleij, [10] North, [11] and Kerton. [12] Among the most widely employed catalysts [13] are binary systems that combine a suitable nucleophile (most often a halide) and a Lewis acid, such as porphyrine, salen and salphen-based derivatives of Al [14] , Mg [15] , Co [16] , Fe [17] , Nb [18] , Zn [19] , alkali metal halides [20] , imidazolium [21] , phosphonium [22] , and ammonium salts. [23] In recent years, organocatalysts have also shown promise as an important alternative in the field of CO2 functionalization.…”

mentioning

confidence: 99%