Lithium Dicyclohexylamide in Transition-Metal-Free Fischer–Tropsch Chemistry

Xu, Maotong; Qu, Zheng‐Wang; Grimme, Stefan; Stephan, Douglas W.

doi:10.1021/jacs.0c11482

Cited by 58 publications

(67 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Hence, 13 CO enriched 3-W shows the C 3 resonance at  = 176.5 ppm. The coupling constants in the chain were determined as 1 JC2-C3 = 41.8 Hz, 1 JC1-C2 = 37.1 Hz, along with 1 JW-C1 = 102 Hz determined from natural abundance satellites of 183 W. Solid-State Characterisation of 2-4: The X-ray structure of 2-Mn incorporates a [7,4] ortho-fused ring system.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Reactions of Aluminium(I) with Transition Metal Carbonyls: Scope, Mechanism and Selectivity of CO Homologation

Kong

Batuecas

Crimmin

2021

Preprint

View full text Add to dashboard Cite

Over the past few decades, numerous model systems have been discovered that create carbon-carbon bonds from CO. These reactions are of potential relevance to the Fischer-Tropsch (F-T) process, a technology that converts syngas mixtures (H 2 /CO) into mixtures of hydrocarbons. In this paper, a new homogeneous model system that constructs carbon chains from CO is reported. The system exploits the cooperative effect of a transition metal complex and main group reductant. An entire reaction sequence from C1 C2 C3 C4 has been synthetically verified. The scope of reactivity is broad and includes a variety of transition metals (M = Cr, Mo, W, Mn, Re, Co), including those found in industrial heterogeneous F-T catalysts. Variation of the transition metal fragment impacts the relative rate of the steps of chain growth, allowing isolation and structural characterisation of a rare C2 intermediate. The selectivity of carbon chain growth is also impacted by this variable; two distinct isomers of the C3 carbon chain were observed to form in different ratios with different transition metal reagents. Based on a combination of experiments (isotope labelling studies, study of intermediates) and calculations (DFT, NBO, ETS-NOCV) we propose a complete mechanism for chain growth that involves defined reactivity at both transition metal and main group centres.

show abstract

Section: Resultsmentioning

confidence: 99%

“…Although we have commented on these types of structures before, some details are included here for clarity. 3 possesses an ortho-fused [6,4] ring system derived from contraction of the [7,4] system in 2, while 4 contains a [6,5] ring system. The side product 3-Re'…”

Section: Resultsmentioning

confidence: 99%

Reactions of Aluminium(I) with Transition Metal Carbonyls: Scope, Mechanism and Selectivity of CO Homologation

Kong

Batuecas

Crimmin

2021

Preprint

View full text Add to dashboard Cite

show abstract

“…The X-ray structure of 2-Mn incorporates a [7,4] ortho-fused ring system. Bond lengths and angles at the main group fragments support the assignment of an aluminium +3 oxidation state.…”

Section: Solid-state Characterisation Of 2-4mentioning

confidence: 99%

Reactions of aluminium(i) with transition metal carbonyls: scope, mechanism and selectivity of CO homologation

2021

View full text Add to dashboard Cite

show abstract

“…Owing to their unique, unquenched reactivities, frustrated Lewis pairs (FLPs) not only demonstrated well-established utilities in small molecular chemistry 28 – 36 but also exhibited unique applications in polymer synthesis 37 – 47 . By selecting a suitable organoaluminum Lewis acid (LA) with appropriate steric hindrance and acidity, we achieved the first example of living polymerization of methacrylates by an authentic FLP 48 .…”

Section: Introductionmentioning

confidence: 99%

Dual-initiating and living frustrated Lewis pairs: expeditious synthesis of biobased thermoplastic elastomers

Bai

Wang

et al. 2021

Nat Commun

View full text Add to dashboard Cite

Biobased poly(γ-methyl-α-methylene-γ-butyrolactone) (PMMBL), an acrylic polymer bearing a cyclic lactone ring, has attracted increasing interest because it not only is biorenewable but also exhibits superior properties to petroleum-based linear analog poly(methyl methacrylate) (PMMA). However, such property enhancement has been limited to resistance to heat and solvent, and mechanically both types of polymers are equally brittle. Here we report the expeditious synthesis of well-defined PMMBL-based ABA tri-block copolymers (tri-BCPs)—enabled by dual-initiating and living frustrated Lewis pairs (FLPs)—which are thermoplastic elastomers showing much superior mechanical properties, especially at high working temperatures (80–130 °C), to those of PMMA-based tri-BCPs. The FLPs consist of a bulky organoaluminum Lewis acid and a series of newly designed bis(imino)phosphine superbases bridged by an alkyl linker, which promote living polymerization of MMBL. Uniquely, such bisphosphine superbases initiate the chain growth from both P-sites concurrently, enabling the accelerated synthesis of tri-BCPs in a one-pot, two-step procedure. The results from mechanistic studies, including the single crystal structure of the dually initiated active species, detailed polymerizations, and kinetic studies confirm the livingness of the polymerization and support the proposed polymerization mechanism featuring the dual initiation and subsequent chain growth from both P-sites of the superbase di-initiator.

show abstract

Lithium Dicyclohexylamide in Transition-Metal-Free Fischer–Tropsch Chemistry

Cited by 58 publications

References 45 publications

Reactions of Aluminium(I) with Transition Metal Carbonyls: Scope, Mechanism and Selectivity of CO Homologation

Reactions of Aluminium(I) with Transition Metal Carbonyls: Scope, Mechanism and Selectivity of CO Homologation

Reactions of aluminium(i) with transition metal carbonyls: scope, mechanism and selectivity of CO homologation

Dual-initiating and living frustrated Lewis pairs: expeditious synthesis of biobased thermoplastic elastomers

Contact Info

Product

Resources

About