BIAN‐Fe(η6‐C6H6): Synthesis, characterization, and l‐lactide polymerization

Brown, Lauren; Wekesa, Francis S.; Unruh, Daniel K.; Findlater, Michael; Long, Brian K.

doi:10.1002/pola.28688

Cited by 31 publications

(12 citation statements)

References 64 publications

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“…[3] The metal-mediated ring-opening polymerization (ROP) of lactides and lactonesi s, nowadays, the most efficient catalytic process for APEs production. Fe complexes activei nt he ROP of cyclic esters are limited, [11][12][13][14][15][16][17][18][19][20][21][22][23] and no examples have been reported that produce cAPEs. [5] Amongo thers, polymers with ac yclic topologya re an intriguing synthetic target because the lack of chain-ends and the high conformational constraintl ead to materialp roperties that are different from their linear analogues.…”

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“…[9] Such materials are highly attractive foru se in spe-cialized fields such as biomedicine. Fe complexes activei nt he ROP of cyclic esters are limited, [11][12][13][14][15][16][17][18][19][20][21][22][23] and no examples have been reported that produce cAPEs. In this regard, the use of ac atalytic system based on ab iocompatiblem etal such as Fe would be of great interest because it would reduce hazards derived from metal residues in the final product.…”

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Cyclic Polyester Formation with an [OSSO]‐Type Iron(III) Catalyst

et al. 2019

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The efficient formationo fc yclic polyesters from the ring-opening polymerization of lactide, e-caprolactone, and b-butyrolactone catalyzed by a1 ,4-dithiabutanedyl-2,2'-bis (4,6-dicumylphenol) [OSSO]-FeCl complex activated with cyclohexene oxide was achieved. The catalystw as very active (initialt urnover frequencyu pt o2 718 h À1 ), robust,a nd workedw ith am onomer/ Fe ratio up to 10 000. The formationo fc yclic polymers was supported by using high-resolution matrix-assisted laser desorptioni onization (MALDI) MS, and the averager ing size ( % 5kDa for cyclic polylactide) independent of the reaction conditions. Am onometallic ring-opening polymerization/cyclization mechanism was proposed from the resultso fakinetic investigation.In the search of viable alternatives to fossil-based plastic materials, one of the most promising classes of sustainable (bio)polymers is aliphatic polyesters (APEs). [1] Indeed, several examples of APEs have been proposed as possible substitutes of well-establishedp olymeric commodities( e.g.,p olystyrene,p olyethylene, andp olypropylene). [2] Amongo thers, poly(lactic acid) (PLA), poly(e-caprolactone) (PCL), and poly(hydroxyb utyrate) (PHB) are the most investigated materials and already on the market. [3] The metal-mediated ring-opening polymerization (ROP) of lactides and lactonesi s, nowadays, the most efficient catalytic process for APEs production. [4] Indeed, av ery high degree of control over the polymerization process has been achieved, which offerst he possibility to obtain polymers with predictable molecular weights, compositions,a nd microstructures. [5] Amongo thers, polymers with ac yclic topologya re an intriguing synthetic target because the lack of chain-ends and the high conformational constraintl ead to materialp roperties that are different from their linear analogues. [6] Different approaches have been proposed for the production of cyclic polymers, [7] andnotable examples have been reported in literature. [8] However,t he formation of cyclic polyesters remains a challenge. [9] Such materials are highly attractive foru se in spe-cialized fields such as biomedicine. Indeed,t he biodistribution of cyclic aliphatic polyesters (cAPEs)i sd ifferent from that of linear APEs, [10] which offers an opportunity to develop new drug deliverys ystems. In this regard, the use of ac atalytic system based on ab iocompatiblem etal such as Fe would be of great interest because it would reduce hazards derived from metal residues in the final product. Fe complexes activei nt he ROP of cyclic esters are limited, [11][12][13][14][15][16][17][18][19][20][21][22][23] and no examples have been reported that produce cAPEs. Actually, the number of reports in which the production of cAPEs by means of aw ell-defined metal complex is described is limited, [24] and mosti nvolve the use of Al- [25][26][27] and Zn-based catalysts. [28] In recent years,wehave developed anumber of Fe catalystsf or the activation of CO 2 and oxiranes for the production of carbonates [29][30][31] anda chieved the...

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Cyclic Polyester Formation with an [OSSO]‐Type Iron(III) Catalyst

et al. 2019

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“…Additionally, some of the most important classes of catalytic applications of BIAN‐Fe (n) are based on hydrofunctionalization ( i. e . hydrogenations, [9a] hydroborations, [8e–g,9b] and hydrosilylations [8a,c–d,9c] ) and polymerization [8b,9d] reactions. Catalytic transformations including carbon‐carbon bond forming reactions, [10] and epoxidations [11] are achieved employing precious metal complexes of BIAN ligands [10–11] .…”

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confidence: 99%

Redox‐Active BIAN‐Based Iron Complexes in Catalysis

Chacón-Terán

Findlater

2022

Eur J Inorg Chem

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α‐Diimine ligands have contributed extensively to the coordination chemistry of the majority of the transition metals; bis(arylimino)acenaphthene ligands (BIANs) have been widely studied and found to offer great versatility in their application as supporting ligands in catalytic transformations. In recent years, BIAN‐based iron complexes have proven effective in mediating a number of reductive transformations which includes hydrosilylation, hydroboration and hydrogenation chemistries. This review highlights the most recent contributions to the field. In our initial 2015 communication, we disclosed that the arene‐capped Fe(0) species ArBIAN−Fe(toluene) mediates aldehyde and ketone hydrosilylation with exceptional activity under solvent‐free conditions. This led us to the discovery that such systems were capable of the hydrosilylation of imines and esters, the hydroboration of imines, aldehydes, ketones, alkenes, and alkynes and even the ring‐opening polymerization of rac‐lactide. Spectroscopic and computational studies have firmly established the importance of redox non‐innocence in BIAN complexes and detailed mechanistic studies have revealed the importance of spin‐state‐crossing in catalysis. Although this work represents only a small component of advances in iron catalysis, our efforts have proven influential in Fe‐based approaches to reductive transformations and is likely to continue to inform the design of Fe‐based catalysts.

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“…Perhaps the most well-known examples are the Ni-BIAN complexes, the so-called Brookhart catalysts, used in industry for ethylene polymerisation [5][6][7][8], while other applications of BIAN complexes have included luminescence properties [9][10][11]. Investigation of the redox non-innocent behaviour of the BIAN ligands have largely been limited to 3d metals (iron, titanium and vanadium) [12][13][14][15][16][17][18]. It has been reported that imines are electrochemically active in the presence of CO 2 [19], and that CO 2 electroreduction occurs as part of an inner sphere electron transfer mechanism [20].…”

Section: Introductionmentioning

confidence: 99%