No abstract

The performance of Multistage Manufacturing Processes (MMPs) can be measured by quality, productivity and cost, which are inversely related to the variation of key product characteristics (KPCs). Therefore, it is crucial to reduce KPCs' variations by not only detecting the changes of process parameters, but also identifying the variation sources and eliminating them with corrective actions. Recent developments in the Stream-of-Variation (SoV) and StatisticalProcess-Control (SPC) methodologies significantly improve the variation reduction for MMPs. This paper provides a review on the reported methodologies by comparing these two categories of methodologies in terms of their variation propagation modeling, process monitoring and diagnostic capability. With an illustrative case study, it is concluded that the recent advancements of SoV and SPC methodologies significantly improve the effectiveness of variation reduction. The discussion on the drawbacks of both methodologies also suggests the future research directions.

We report an unprecedented, efficient nickel‐catalysed radical relay for the remote cross‐electrophile coupling of β‐bromo‐α‐benzylamino acid esters with aryl bromides via 1,4‐aryl migration/arylation cascades. β‐Bromo‐α‐benzylamino acid esters are considered as unique molecular scaffolds allowing for aryl migration reactions, which are conceptually novel variants for the radical Truce–Smiles rearrangement. This reaction enables the formation of two new C(sp3)−C(sp2) bonds using a bench‐stable Ni/bipyridine/Zn system featuring a broad substrate scope and excellent diastereoselectivity, which provides an effective platform for the remote aryl group migration and arylation of amino acid esters via redox‐neutral C(sp3)−C(sp2) bond cleavage. Mechanistically, this cascade reaction is accomplished by combining two powerful catalytic cycles consisting of a cross‐electrophile coupling and radical 1,4‐aryl migration through the generation of C(sp3)‐centred radical intermediates from the homolysis of C(sp3)−Br bonds and the switching of the transient alkyl radical into a robust α‐aminoalkyl radical.

No abstract

No abstract