Hydrogenolysis reactions of so-called lignin model dimers using a Ru-xantphos catalyst are presented (xantphos = 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene). For example, of some nine models studied, the alcohol, 2-(2-methoxyphenoxy)-1-phenylethanol (1), with 5 mol% Ru(H)(2)(CO)(PPh(3))(xantphos) (18) in toluene-d(8) at 135 °C for 20 h under N(2), gives in ~95% yield the C-O cleavage hydrogenolysis products, acetophenone (14) and guaiacol (17), and a small amount (<5%) of the ketone, 2-(2-methoxyphenoxy)-1-phenylethanone (4), as observed by (1)H NMR spectroscopy. The in situ Ru(H)(2)(CO)(PPh(3))(3)/xantphos system gives similar findings, confirming a recent report (J. M. Nichols et al., J. Am. Chem. Soc., 2010, 132, 12554). The active catalyst is formulated 'for convenience' as 'Ru(CO)(xantphos)'. The hydrogenolysis mechanism proceeds by initial dehydrogenation to give the ketone 4, which then undergoes hydrogenolysis of the C-O bond to give 14 and 17. Hydrogenolysis of 4 to 14 and 17 also occurs using the Ru catalyst under 1 atm H(2); in contrast, use of 3-hydroxy-2-(2-methoxyphenoxy)-1-phenyl-1-propanone (7), for example, where the CH(2) of 4 has been changed to CHCH(2)OH, gives a low yield (≤15%) of hydrogenolysis products. Similarly, the diol substrate, 2-(2-methoxyphenoxy)-1-phenyl-1,3-propanediol (9), gives low yields of hydrogenolysis products. These low yields are due to formation of the catalytically inactive complexes Ru(CO)(xantphos)[C(O)C(OC(6)H(4)OMe)=C(Ph)O] (20) and/or Ru(CO)(xantphos)[C(O)CH=C(Ph)O] (21), where the organic fragments result from dehydrogenation of CH(2)OH moieties in 7 and 9. Trace amounts of Ru(CO)(xantphos)(OC(6)H(4)O), a catecholate complex, are isolated from the reaction of 18 with 1. Improved syntheses of 18 and lignin models are also presented.

While acetylcholinesterase inhibitors are used to treat a wide range of patients with Alzheimer’s disease, acetylcholinesterase inhibitor use has also been associated with a variety of cardiovascular complications, including bradycardia and syncope. Herein, we review the pathophysiology and clinical evidence for cardiovascular complications caused by acetylcholinesterase inhibitors in patients being treated for dementia and discuss options for their management.

A 31-year-old male was referred for a stress test due to worsening palpitations and chest pressure. His clinic 12-lead electrocardiogram was normal. At the time of his stress test, his pre-exercise electrocardiogram revealed an intermittent short PR interval with a delta wave. This pattern resolved during exercise, but in recovery he experienced paroxysms of supraventricular tachycardia. Imaging revealed low left ventricular ejection fraction. Given the diagnosis of Wolff-Parkinson-White Syndrome, he underwent radiofrequency ablation. His cardiomyopathy was presumed to be secondary to his Wolff-Parkinson-White, and an echocardiogram a few months later showed normalization of his left ventricular ejection fraction.

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Since the mid-1990s, the US has seen a decline in research activities in medical education and academic health care centers. Our goal was to offer a multidisciplinary experience for undergraduates to participate in a practical, hands-on research experience to increase the likelihood of entering STEM research careers. The authors structured a collaborative teaching environment to lead a group of over 25 undergraduate and graduate students in clinical research activities as part of the resident author's research program during psychiatry graduate training. A particularly innovative component of this work, making the timeline and technical analysis possible, was the partnership with an industry sponsor. Much of the teaching program's structure was inspired by the analogous program of the industry sponsor. This provided a structured clinical research experience for undergraduates, providing opportunities to participate in the study design, patient recruitment and enrollment, data collecti on and analysis phases of the project with more autonomy than typically available at this level of training. Students favored the experience with generally positive ratings of the program. Students gained skills and felt more comfortable in practical aspects of research and stated they were more likely to pursue a research career after this experience. This method may be a solution for other clinical trainees given their limited time and funding while serving to increase exposure to STEM research earlier in life to reverse the trend of declining research activity. This method can be used across other training institutions at different scales to achieve similar goals.