This review surveys the synthesis and reactivity of low-oxidation state metalate anions of the d-block elements, with an emphasis on contributions reported between 2006 and 2022. Although the field ...has a long and rich history, the chemistry of transition metalate anions has been greatly enhanced in the last 15 years by the application of advanced concepts in complex synthesis and ligand design. In recent years, the potential of highly reactive metalate complexes in the fields of small molecule activation and homogeneous catalysis has become increasingly evident. Consequently, exciting applications in small molecule activation have been developed, including in catalytic transformations. This article intends to guide the reader through the fascinating world of low-valent transition metalates. The first part of the review describes the synthesis and reactivity of d-block metalates stabilized by an assortment of ligand frameworks, including carbonyls, isocyanides, alkenes and polyarenes, phosphines and phosphorus heterocycles, amides, and redox-active nitrogen-based ligands. Thereby, the reader will be familiarized with the impact of different ligand types on the physical and chemical properties of metalates. In addition, ion-pairing interactions and metal–metal bonding may have a dramatic influence on metalate structures and reactivities. The complex ramifications of these effects are examined in a separate section. The second part of the review is devoted to the reactivity of the metalates toward small inorganic molecules such as H2, N2, CO, CO2, P4 and related species. It is shown that the use of highly electron-rich and reactive metalates in small molecule activation translates into impressive catalytic properties in the hydrogenation of organic molecules and the reduction of N2, CO, and CO2. The results discussed in this review illustrate that the potential of transition metalate anions is increasingly being tapped for challenging catalytic processes with relevance to organic synthesis and energy conversion. Therefore, it is hoped that this review will serve as a useful resource to inspire further developments in this dynamic research field.
Despite the accessibility of numerous transition metal polyphosphido complexes through transition‐metal‐mediated activation of white phosphorus, the targeted functionalization of Pn ligands to obtain ...functional monophosphorus species remains challenging. In this study, we introduce a new 3+1 fragmentation procedure for cyclo‐P4 ligands, leading to the discovery of acylcyanophosphanides and ‐phosphines. Treatment of the complex K(18c‐6)(Ar*BIAN)Co(η4‐P4) (K(18c‐6)3, 18c‐6=18crown‐6, Ar*=2,6‐dibenzhydryl‐4‐isopropylphenyl, BIAN=1,2‐bis(arylimino)acenaphthene diimine) with acyl chlorides results in the formation of acylated tetraphosphido complexes (Ar*BIAN)Co(η4‐P4C(O)R) (R=tBu, Cy, 1‐Ad, Ph; 4 a–d). Subsequent reactions of 4 a–d with cyanide salts yield acylated cyanophosphanides RC(O)PCN− (9 a–d−) and the cyclo‐P3 cobaltate anion (Ar*BIAN)Co(η3‐P3)(CN)− (8−). Further reactions of 4 a–d with trimethylsilyl cyanide (Me3SiCN) and isocyanides provide insight into a plausible mechanism of this 3+1 fragmentation reaction, as these reagents partially displace the P4C(O)R ligand from the cobalt center. Several potential intermediates of the 3+1 fragmentation were characterized. Additionally, the introduction of a second acyl substituent was achieved by treating K(18c‐6)9b with CyC(O)Cl, resulting in the first bis(acyl)monocyanophosphine (CyC(O))2PCN (10).
White phosphorus (P4) can be selectively activated and functionalized via low‐valent cobalt complexes. Subsequent treatment of the acylated P4 ligands with cyanide induces a rare 3+1 fragmentation and yields cyanophosphanides (P1) and triphosphido cobaltate (P3). Additional experiments with neutral cyanide or isocyanide provide insight into a plausible fragmentation mechanism and allow the isolation of potential intermediates.
Although numerous polyphosphido complexes have been accessed through the transition-metal-mediated activation and functionalization of white phosphorus (P
), the selective functionalization of the ...resulting polyphosphorus ligands in these compounds remains underdeveloped. In this study, we explore the reactions between cyclotetraphosphido cobalt complexes and heterocumulenes, leading to functionalized P
ligands. Specifically, the reaction of carbon disulfide (CS
) with K(18c-6)(Ar*BIAN)Co(η
-P
) (K(18c-6)
, 18c-6 = 18crown-6) affords the adduct K(18c-6)(Ar*BIAN)Co(η
:η
-P
CS
) (K(18c-6)
), in which CS
is attached to a single phosphorus atom (Ar* = 2,6-dibenzhydryl-4-isopropylphenyl, BIAN = 1,2-bis(arylimino)acenaphthene diimine). In contrast, the insertion of bis(trimethylsilyl)sulfur diimide S(NSiMe
)
into a P-P bond of K(18c-6)
yields K(18c-6)(Ar*BIAN)Co(η
:η
-P
SN
(SiMe
)
) (K(18c-6)
). This salt further reacts with Me
SiCl to form (Ar*BIAN)Co(η
:η
-P
SN
(SiMe
)
(
), featuring a rare azatetraphosphole ligand. Moreover, treatment of the previously reported complex (Ar*BIAN)Co(η
:η
-P
C(O)
Bu) (
) with isothiocyanates results in P-C bond insertion, yielding (Ar*BIAN)Co(η
:η
-P
C(S)N(R)C(O)
Bu) (
,
; R = Cy, Ph).
We show that countercations exert a remarkable influence on the ability of anionic cobaltate salts to catalyze challenging alkene hydrogenations. An evaluation of the catalytic properties of ...CatCo(η4‐cod)2 (Cat=K (1), Na (2), Li (3), (Depnacnac)Mg (4), and N(nBu)4 (5); cod=1,5‐cyclooctadiene, Depnacnac={2,6‐Et2C6H3NC(CH3)}2CH)) demonstrated that the lithium salt 3 and magnesium salt 4 drastically outperform the other catalysts. Complex 4 was the most active catalyst, which readily promotes the hydrogenation of highly congested alkenes under mild conditions. A plausible catalytic mechanism is proposed based on density functional theory (DFT) investigations. Furthermore, combined molecular dynamics (MD) simulation and DFT studies were used to examine the turnover‐limiting migratory insertion step. The results of these studies suggest an active co‐catalytic role of the counterion in the hydrogenation reaction through the coordination to cobalt hydride intermediates.
The counterion makes a difference in alkene hydrogenations promoted by low‐valence cobaltate salts. The best performing catalyst cleanly hydrogenated various alkenes (including tri‐ and tetra‐substituted) under mild conditions. Mechanistic studies point toward a homotopic catalyst and show how counterion coordination to hydride intermediates modulates the barrier for the turnover‐limiting migratory insertion.
The primary aim of this study was to evaluate the agreement between surgeons and two validated total knee arthroplasty (TKA) appropriateness tools, and secondarily to compare Australian ...appropriateness rates to those reported internationally.
A consecutive sample of patients from one public hospital arthroplasty clinic and a convenience sample from private rooms of surgeons in New South Wales, Australia (n = 11), referred for surgical opinion regarding TKA were enrolled over 1 year. Surgeons applied appropriateness tools created by Escobar et al. and the American Academy of Orthopaedic Surgeons (AAOS). Correlation between the appropriateness tools and surgeon's decisions were evaluated.
There were 368 patients enrolled, and contrasting rates of being “appropriate” for surgery were identified between the Escobar (n = 109, 29.6%) and AAOS (n = 292, 79.3%) tools. Surgeon agreement with the Escobar tool was substantial (ĸ = 0.61, 95%CI: 0.53–0.69) compared to slight with the AAOS tool (ĸ = 0.11, 95%CI: 0.06–0.16). Of those advised against TKA (n = 179, 48.6%), the AAOS tool suggested many patients (n = 111, 62.0%) were “appropriate” compared to the Escobar tool (n = 12, 6.7%).
Surgeons rated patients seeking opinion for TKA as appropriate over half the time, however the AAOS tool had low correlation with surgeons as opposed to the Escobar tool. This was illustrated by both tools rating a majority of patients to be operated on as appropriate, but only the AAOS tool considering most patients not chosen for surgery to be appropriate. When comparing previously published appropriateness rates, appropriateness in Australia, USA, Spain and Qatar was found to be similar.
σ‐Bond metathesis reactions between (6‐Dipp)CuOtBu (6‐Dipp=:C({Dipp}NCH2)2CH2, Dipp=2,6‐iPr2−C6H3) and three diboranes gave access to three new copper(I) boryl complexes (6‐Dipp)CuBcat, ...(6‐Dipp)CuBneop, and (6‐Dipp)CuBhex (cat=1,2‐O2C6H4; neop=(OCH2)2C(CH3)2; hex=OC(CH3)HCH2C(CH3)2O). Whilst (6‐Dipp)CuBcat and (6‐Dipp)CuBneop formed rapidly in toluene, access to (6‐Dipp)CuBhex required heating to 60 °C for days. The complexes were characterised by single‐crystal X‐ray crystallography which showed in all three cases that the systems were monomers and distorted‐linear at the copper atom. The stability of (6‐Dipp)CuBneop was found to be comparable to that of (IPr*)Cu‐Bneop (IPr*=1,3‐bis(2,6‐(diphenylmethyl)‐4‐methylphenyl)imidazol‐2‐ylidene); it persisted in solution for days with no sign of decomposition. (6‐Dipp)CuBhex is a rare crystallographically characterised example of a complex containing a boryl anion supported by the hexylene glycolato ligand.
A ring‐expanded NHC with flanking di‐iso‐propylphenyl groups has been shown to support 3 copper(I) boryl systems. This allows the structural characterisation of (6‐Dipp)CuBcat, (6‐Dipp)CuBneop, and (6‐Dipp)CuBhex (cat=1,2‐O2C6H4; neop=(OCH2)2CMe2; hex=OC(CH3)HCH2C(CH3)2O). All three compounds are reasonably stable, readily isolable sources of boryl nucleophiles, and (6‐Dipp)CuBhex is a rare example of a boryl anion bearing the hexylene glycol ester.
The theme of suffering is intimately tied to the possibilities of the blood as redemptive in theology. Potentially considered a universal pathway to salvation and racial transcendence for people of ...African descent, “Da Blood of Shesus” asks: Is there redeeming power in the blood for people of African descent? Turning to Womanist and lyrical theologians to postulate an African theological framework which explores redemptive suffering not glorified as inevitable and intricate to the historical Black experience and the church. Lyrical theologians affirm Jesus’ redemptive power of the blood in Hip Hop portraying the ways in which the cross reveals the attributes of God. Womanist theologians challenge the “classical” interpretation of redemptive suffering, illuminating the ways it contributes to Black oppression and wretchedness. Arguably, Womanist and lyrical theologians conjointly point towards liberatory and alternatives to examine redemptive suffering for people of African descent by offering sites to scrutinize and nuance the blood as an indispensable pathway to redemption. An African theological perspective decenters the logics of anti-Blackness proposing suffering is inevitable to Black life and the historical Black experience.
This article evaluates the application of ‘incident control’ methodology usually applied in communicable disease control to an ‘incident’ of unexplained deaths, specifically to resolve a significant ...difference in 1-year survival after a lung cancer diagnosis observed between two Clinical Commissioning Groups and the England national average, 2011–14. The purpose of the evaluation was to assess whether a formalised incident control approach is feasible and effective in improving outcomes for non-communicable diseases.
Descriptive, qualitative, process evaluation.
There were two components to the evaluation: a document review against identified phases of a non-communicable disease incident control framework and a qualitative analysis of semi-structured interviews with stakeholders who had been involved in implementation.
The findings indicate feasibility of the incident control model, with some limitations. Identified strengths of the model included the articulation of a clear case and incident definition. The structure and stepped phased approach facilitated partner engagement, robust data analysis, action planning and communication strategies. Delays in data publication and the lack of comparable data across different non-communicable diseases present challenges in timely response and prioritisation of ‘incidents’.
The evaluation indicates value in applying defined incident control methodology to management of non-communicable diseases, especially where there is identification of a potential outlier or a measurable variation, i.e. there is a definable ‘incident’ and ‘case’.
![Cobalt‐Mediated [3+1] Fragm...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/1433-7851/small "Cobalt‐Mediated [3+1] Fragmentation of White Phosphorus: Access to Acylcyanophosphanides")
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