Herein, we report further improvements to the synthesis of tenofovir 1, the precursor to tenofovir disoproxil fumarate and tenofovir alafenamide fumarate. Starting from acyclic precursor diaminomalononitrile 12, a four-step protocol to tenofovir 1 will allow for vertical integration for more manufacturers. The key transformation is a more convergent one step procedure from 6 as compared to the current commercial process, with an improved yield from 59% (two steps) to 70%. Further improvements include eliminating the need for problematic magnesium tert-butoxide (MTB) and significant solvent reduction by eliminating the need for an intermediate workup. With the costs of HIV/AIDS treatments remaining a barrier for those most in need, lowering the raw material/processing costs and increasing the security of supply can increase patient access. File list (2) download file view on ChemRxiv An_Efficient_Synthesis_of_Tenofovir_(PMPA)_Derstine... (803.91 KiB) download file view on ChemRxiv An_Efficient_Synthesis_of_Tenofovir_(PMPA)_Derstine_... (1.96 MiB)

Aqueous conditions were developed for conducting an open-to-air, copper(II)-catalyzed addition of pinBBdan to alkynoates and alkynamides. The simple and mild β-borylation protocol proceeds in a remarkably chemo-, regio-, and stereoselective fashion to afford 1,8-diaminonaphthalene protected (Z)-β-boryl enoates and primary, secondary, and tertiary enamides in good to excellent yields. These reactions demonstrate a high tolerance toward a variety of alkyl, aryl, and heteroatom functional groups and provide convenient access to a diverse range of vinylboronic acid derivatives.

We have studied the plasmon-driven photoreaction of a dual thiol-anchored o-nitrobenzyl-based photouncaging ligand on silver nanoparticles. Previous results have shown that this compound strongly anchors to gold surfaces, and a 1 J/cm 2 dose of UV light induces the intended photoreaction, uncaging an amine on the surface. This allows for photopatterning and the selective adhesion of gold nanospheres (AuNSs) to a surface via electrostatic attraction between the positively charged amines and negatively charged AuNSs. Here, we report that when the ligand is adsorbed on a silver nanospheroid film (AgNS), an additional photoreaction induced by green light inhibits AuNSs adhesion in the UV exposed film. Our findings suggest that this is a result of the neutralization of the amine group's ability to become charged, as opposed to the removal of the ligand from the surface of the silver nanospheroids. We hypothesize that this neutralization may be due to a form of hot-hole-induced photocatalysis, resulting in an NN double bond between two neighboring ligands. This reaction has been documented in similarly amine-terminated moieties. This neutralization allows for a more fine-tuned, plasmonically based control of the ligand's photoreaction, as the green light exposure only affects the ligand if it has previously been cleaved by UV light, and makes it possible to perform reverse photopatterning on the surface.

The diboration of substituted propargylic alcohols has been achieved using a bimetallic Pd/Cu catalyst system. In situ formation of a pentrafluoroboronic acid intermediate sufficiently activates the C-O bond towards dual...