Pure amine-bis(phenol) ligands are readily accessible in high yield, often >90%, when the Mannich condensation reactions are performed “on water” or in poly(ethyleneglycol) (PEG). Microwave-assisted synthesis dramatically reduces the time and energy required to prepare these molecules, typically from 24 h to 5 min. The approach seems to be widely applicable (7 amines and 5 phenols were tested to yield a diverse set of bis(phenol) ligands). Significant improvements in yield were observed for ligands derived from di-tert-amyl and di-tert-butyl phenols, possibly resulting from a hydrophobic effect. Single crystal X-ray diffraction data for the ligand derived from p-cresol and N,N′-dimethylethylenediamine is reported.Key words: amine-phenol, Mannich condensation, on water, microwave, ligand, high-throughput.
Reaction of two equivalents of n-BuLi with sterically demanding amine-bis(phenol) compounds, H 2 O 2 NN R (Me 2 NCH 2 CH 2 N{CH 2 -3,5-R 2 -C 6 H 2 OH} 2 ; R = t-Bu or t-Pe (tert-pentyl)) yields isolable lithium complexes, Li 2 (O 2 NN R ), in good yields. Upon reaction with one equivalent of LnCl 3 (THF) x , the lithium salts afford rare earth amine-phenolate chloride complexes in good yields, Ln(O 2 NN R )Cl(THF); Ln = Y, Yb, Ho, Gd, Sm, Pr. Crystals of Y(O 2 NN t-Bu )Cl(THF), 1, and Sm(O 2 NN t-Bu )Cl(DME), 2, suitable for single crystal X-ray crystallographic analysis were obtained. In contrast to previously reported [{Gd(O 2 NN t-Pe )(THF)(l-Cl)} 2 ] and related La and Sm complexes, these species are monomeric. 1 contains Y in a distorted octahedral environment bonded to two amine, two phenolate, one THF and one chloride donor. 2 contains Sm in a distorted capped trigonal prismatic environment bonded to two amine, two phenolate, two DME oxygens and one chloride donor. The Ln(O 2 NN t-Pe )Cl(THF) complexes were active initators for the controlled ring-opening polymerization of e-caprolactone with a tendency to form low molecular weight cyclic polyesters (M n 3000-5000). The conversion rates, although slower than related amido and alkyl species, were different for monomeric and dimeric initiators. The size of the metal centre also affected the conversions and the molecular weights achieved.
Objectives Evaluate web-based patient-reported outcome (wbPRO) collection in MS subjects in terms of feasibility, reliability, adherence, and subject-perceived benefits; and quantify the impact of MS-related symptoms on perceived well-being. Methods Thirty-one subjects with MS completed wbPROs targeting MS-related symptoms over six months using a customized web portal. Demographics and clinical outcomes were collected in person at baseline and six months. Results Approximately 87% of subjects completed wbPROs without assistance, and wbPROs strongly correlated with standard PROs (r > 0.91). All wbPROs were completed less frequently in the second three months (p < 0.05). Frequent wbPRO completion was significantly correlated with higher step on the Expanded Disability Status Scale (EDSS) (p = 0.026). Nearly 52% of subjects reported improved understanding of their disease, and approximately 16% wanted individualized wbPRO content. Over half (63.9%) of perceived well-being variance was explained by MS symptoms, notably depression (rs = −0.459), fatigue (rs = −0.390), and pain (rs = −0.389). Conclusions wbPRO collection was feasible and reliable. More disabled subjects had higher completion rates, yet most subjects failed requirements in the second three months. Remote monitoring has potential to improve patient-centered care and communication between patient and provider, but tailored PRO content and other innovations are needed to combat declining adherence.
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