Encoding laboratory testing data: case studies of the national implementation of HHS requirements and related standards in five laboratories.

OBJECTIVE: Assess the effectiveness of providing Logical Observation Identifiers Names and Codes (LOINC®)-to-In Vitro Diagnostic (LIVD) coding specification, required by the United States Department of Health and Human Services for SARS-CoV-2 reporting, in medical center laboratories and utilize findings to inform future United States Food and Drug Administration policy on the use of real-world evidence in regulatory decisions. MATERIALS AND METHODS: We compared gaps and similarities between diagnostic test manufacturers' recommended LOINC® codes and the LOINC® codes used in medical center laboratories for the same tests. RESULTS: Five medical centers and three test manufacturers extracted data from laboratory information systems (LIS) for prioritized tests of interest. The data submission ranged from 74 to 532 LOINC® codes per site. Three test manufacturers submitted 15 LIVD catalogs representing 26 distinct devices, 6956 tests, and 686 LOINC® codes. We identified mismatches in how medical centers use LOINC® to encode laboratory tests compared to how test manufacturers encode the same laboratory tests. Of 331 tests available in the LIVD files, 136 (41%) were represented by a mismatched LOINC® code by the medical centers (chi-square 45.0, 4 df, P < .0001). DISCUSSION: The five medical centers and three test manufacturers vary in how they organize, categorize, and store LIS catalog information. This variation impacts data quality and interoperability. CONCLUSION: The results of the study indicate that providing the LIVD mappings was not sufficient to support laboratory data interoperability. National implementation of LIVD and further efforts to promote laboratory interoperability will require a more comprehensive effort and continuing evaluation and quality control.

Unusual reactivities of N-heterocyclic carbenes upon coordination to the platinum(II)-dimethyl moiety.

Unsaturated NHCs of varying steric bulk undergo a series of unusual oxidative addition and reductive elimination processes upon binding to the Pt(Me)(2) fragment.

Synthesis and characterization of [Cu(NHC)2]X complexes: catalytic and mechanistic studies of hydrosilylation reactions.

The preparation of two series of [Cu(NHC)2]X complexes (NHC=N-heterocyclic carbene, X=PF6 or BF4) in high yields from readily available materials is reported. These complexes have been spectroscopically and structurally characterized. The activity of these cationic bis-NHC complexes in the hydrosilylation of ketones was examined, and both the ligand and the counterion showed a significant influence on the catalytic performance. Moreover, when compared with related [Cu(NHC)]-based systems, these cationic complexes proved to be more efficient under similar reaction conditions. The activation step of [Cu(NHC)2]X precatalysts towards hydrosilylation was investigated by means of 1H NMR spectroscopy. Notably, it was shown that one of the N,N'-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr) ligands in [Cu(IPr)2]BF4 is displaced by tBuO(-) in the presence of NaOtBu, producing the neutral [Cu(IPr)(OtBu)]. This copper alkoxide is known to be a direct precursor of an NHC-copper hydride, the actual active species in this transformation. Furthermore, reagent loading and counterion effects have been rationalized in light of the species formed during the reaction.

Modified (NHC)Pd(allyl)Cl (NHC = N-heterocyclic carbene) complexes for room-temperature Suzuki-Miyaura and Buchwald-Hartwig reactions.

A series of (NHC)Pd(R-allyl)Cl complexes [NHC: IPr = N,N'-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, SIPr = N,N'-bis(2,6-diisopropylphenyl)-4,5-dihydroimidazol-2-ylidene; R = H, Me, gem-Me2, Ph] have been synthesized and fully characterized. When compared to (NHC)Pd(allyl)Cl, substitution at the terminal position of the allyl scaffold favors a more facile activation step. This translates into higher catalytic activity in the Suzuki-Miyaura and Buchwald-Hartwig reactions, allowing for the coupling of unactivated aryl chlorides at room temperature in minutes. In the Suzuki-Miyaura reaction, aryl triflates, bromides, and chlorides react with boronic acids using very low catalyst loading. In the N-aryl amination reaction, a wide range of substrates has been coupled efficiently; primary-, secondary-, alkyl-, or aryl-amines react in high yields with unactivated, neutral, and activated aryl chlorides and bromides. In both reactions, extremely hindered substrates such as tri-ortho-substituted biaryls and tetra-ortho-substituted diarylamines can be produced without loss of activity. Finally, the present catalytic system has proven to be efficient with as low as 10 parts-per-million (ppm) of precatalyst in the Buchwald-Hartwig reaction and 50 ppm in the Suzuki-Miyaura reaction.

Interaction of a bulky N-heterocyclic carbene ligand with Rh(I) and Ir(I). Double C-H activation and isolation of bare 14-electron Rh(III) and Ir(III) complexes.

Reactivity and structural studies of unusual rhodium and iridium systems bearing two N-heterocyclic carbene (NHC) ligands are presented. These systems are capable of intramolecular C-H bond activation and lead to coordinatively unsaturated 16-electron complexes. The resulting complexes can be further unsaturated by simple halide abstraction, leading to 14-electron species bearing an all-carbon environment. Saturation of the vacant sites in the 16- and 14-electron complexes with carbon monoxide permits a structural comparison. DFT calculations show that these electrophilic metal centers are stabilized by pi-donation of the NHC ligands.

Steric and electronic properties of N-heterocyclic carbenes (NHC): a detailed study on their interaction with Ni(CO)4.

N-heterocyclic carbene ligands IMes (1), SIMes (2), IPr (3), SIPr (4), and ICy (5) react with Ni(CO)(4) to give the saturated tricarbonyl complexes Ni(CO)(3)(IMes) (8), Ni(CO)(3)(SIMes) (9), Ni(CO)(3)(IPr) (10), Ni(CO)(3)(SIPr) (11), and Ni(CO)(3)(ICy) (12), respectively. The electronic properties of these complexes have been compared to their phosphine analogues of general formula Ni(CO)(3)(PR(3)) by recording their nu(CO) stretching frequencies. While all of these NHCs are better donors than tertiary phosphines, the differences in donor properties between ligands 1-5 are surprisingly small. Novel, unsaturated Ni(CO)(2)(IAd) (13) and Ni(CO)(2)(I(t)()Bu) (14) compounds are obtained from the reaction of Ni(CO)(4) with IAd (6) and I(t)()Bu (7). Complexes 13 and 14 are highly active toward substitution of the NHC as well as the carbonyl ligands. This has allowed the determination of Ni-C(NHC) bond dissociation energies and the synthesis of various unsaturated Ni(0) and Ni(II) complexes. Computational studies on compounds 8-14 are in line with the experimental findings and show that IAd (6) and I(t)()Bu (7) are more bulky than IMes (1), SIMes (2), IPr (3), SIPr (4), and ICy (5). Furthermore, a method based on %V(bur) values has been developed for the direct comparison of steric requirements of NHCs and tertiary phosphines. Complexes 8-14, as well as NiCl(C(3)H(5))(I(t)()Bu) (16) and NiBr(C(3)H(5))(I(t)()Bu) (17), have been characterized by X-ray crystallography.

Reactivity of a N-heterocyclic carbene, 1,3-di-(1-adamantyl) imidazol-2-ylidene, with a pseudo-acid: structural characterization of Claisen condensation adduct.

The reactivity of a N-heterocyclic carbene (NHC) with a pseudo-acid (ester in this case) is described. The product results from an unusual C-H bond activation. The structure of the product has been established by a single crystal diffraction study.

A Striking, Multifaceted, Decalithium Aggregate with Carbanion, Organoamide, and Alkoxide Functionalities.

The three most important "superbase" anionic building blocks are contained in the striking decalithium aggregate in the structure of which a single lithium atom is surrounded solely by an amide, an alkoxide, and a carbanion.