Tris­[N,N-bis­(trimethylsilyl)­amide]lanthanum (LaNTMS) is an efficient and selective homogeneous catalyst for the deoxygenative reduction of tertiary and secondary amides with pinacolborane (HBpin) at mild temperatures (25–60 °C). The reaction, which yields amines and O­(Bpin)2, tolerates nitro, halide, and amino functional groups well, and this amide reduction is completely selective, with the exclusion of both competing inter- and intramolecular alkene/alkyne hydroboration. Kinetic studies indicate that amide reduction obeys an unusual mixed-order rate law which is proposed to originate from saturation of the catalyst complex with HBpin. Kinetic and thermodynamic studies, isotopic labeling, and DFT calculations using energetic span analysis suggest the role of a [(Me3Si)2N]2La-OCHR­(NR′2)­[HBpin] active catalyst, and hydride transfer is proposed to be ligand-centered. These results add to the growing list of transformations that commercially available LaNTMS is competent to catalyze, further underscoring the value and versatility of lanthanide complexes in homogeneous catalysis.

After the inhibition of acetylcholinesterase (AChE) by organophosphorus (OP) nerve agents, a dealkylation reaction of the phosphylated serine, referred to as aging, can occur. When aged, known reactivators of OP-inhibited AChE are no longer effective. Realkylation of aged AChE may provide a route to reversing aging. We designed and synthesized a library of quinone methide precursors (QMPs) as proposed realkylators of aged AChE. Our lead compound (C8) from an in vitro screen successfully resurrected 32.7 and 20.4% of the activity of methylphosphonate-aged and isopropyl phosphate-aged electric-eel AChE, respectively, after 4 days. C8 displays properties of both resurrection (recovery from the aged to the native state) and reactivation (recovery from the inhibited to the native state). Resurrection of methylphosphonate-aged AChE by C8 was significantly pH-dependent, recovering 21% of activity at 4 mM and pH 9 after only 1 day. C8 is also effective against isopropyl phosphate-aged human AChE.

Homoleptic lanthanide trisamides provide a simple and highly accessible bridge between organolanthanide chemistry and the synthetic methodology community, and although they have proven to be competent catalysts in a wide variety of unique transformations, their reactivity, scope, and mechanism remain understudied relative to lanthanide metallocenes and related organometallic catalysts. In this Perspective, we provide a critical review of the recent advances in homoleptic lanthanide-mediated catalysis as they apply to atom-efficient and environmentally benign organic syntheses. Instead of an exhaustive review, we focus on selected examples of the unexpected reactivity displayed by readily available Ln­[N­(SiMe3)2]3 complexes. By focusing on both the experimental as well as theoretical and mechanistic aspects of this work, we seek to highlight the value, versatility, and underlying concepts governing the unusual catalytic properties of homoleptic lanthanide amides and offer a general outlook on the prospects for this field.

The COVID-19 pandemic has led to an acute shortage of hand sanitizer, which is crucial to keeping people safe and to preventing the spread of the SARS-CoV-2 virus. However, universities across the world have used their expertise to help to meet urgent demand from public bodies and the emergency services for supplies of safe and effective sanitizer. We explore here the experience of the University of Bristol, UK, in negotiating the regulatory demands and logistical challenges facing its own sanitizer production efforts. We also reflect on the different regulatory situation for US colleagues pursuing similar activities, and we share our advice for other universities wishing to follow a similar path.

The binuclear salphen Ti polymerization catalyst N,N′-1,2-phenylene­[(salicylideneaminato)­Ti­(Cp*)­Me2)]2 (2) is synthesized by reaction of salphen-H2 with Cp*TiMe3. Mononuclear [N-(2,6-diisopropyl)­phenyl­(salicylidene­aminato)]­Ti­(Cp*)­Me2 (1) serves as a control. Activation studies of 2 with cocatalyst Ph3C+­B­(C6F5)4 – yield the cationic polymerization-inactive complex [N,N′-1,2-phenylene­(salicylidene­aminato)­Ti­(Cp*)]+­B­(C6F5)4 – (4) and polymerization-active Cp*TiMe2 +­B­(C6F5)4 –. Polymerization studies comparing 2 with Cp*TiMe 3 suggest that, within the catalytic time frame, while 2 retains bimetallic character under an ethylene atmosphere, it rapidly decomposes to 4 and Cp*TiMe2 + in the presence of 1-hexene. These monomer-dependent reorganization results highlight the importance of olefin polymerization activation mechanistic studies while providing insight for improved bimetallic catalyst design.