Droplet-Enhanced Asymmetric Catalysis: Squaramide-Derived Pseudopeptide for Enantioselective Addition Reactions.

July 20, 2026| Source: Journal of the American Chemical Society

Droplets formed through phase separation represent an emerging strategy to enhance enzyme-mimetic catalysis, demonstrating significant potential in catalytic science. However, due to the lack of systematic methodologies for precise engineering of chiral microenvironments within droplets, their application to asymmetric catalysis remains largely unexplored. To address this challenge, we integrate l -phenylalanine into an L-tert -leucine-derived squaramide to design the squaramide-derived pseudopeptide droplets. This catalytic system demonstrates remarkably enhanced catalytic performance in the enantioselective conjugate addition of α-nitrosulfone to acrylates and enones, as well as Michael addition of acetylacetone to β-nitroalkenes. Mechanistic investigations reveal that the increased local substrate concentration significantly enhances reactivity, while the engineered favorable chiral microenvironment boosts enantioselectivity. This study establishes a methodological framework for elucidating differentiated catalytic behaviors within the droplets, thereby advancing the design and application of droplet-based asymmetric catalytic systems.

Read the original source →

Reversing vegetable biodiversity loss to diversify diets.

Vegetables are a critical component of diets, with inadequate intake of this essential food group leading to poor dietary quality and malnutrition. Food system assessments identify insufficient production, comparatively high prices, and sociocultural barriers as key constraints to vegetable consumption. We argue that vegetable biodiversity, spanning vegetable species and their varieties, as well as their wild relative species, is a central yet underutilized lever for enhancing vegetable consumpt

EnvironmentAugust 4, 2026

Sediment accumulation rate predicts the temporal resolution of marine fossil assemblages.

Time averaging (TA), the mixing of noncontemporaneous organisms in fossil assemblages, governs the resolution of paleontological data and determines which biological and environmental processes are recorded in the geological record. To assess variation in TA and its dependence on external drivers, we used amino acid and radiocarbon methods to individually date 7,593 specimens across 384 samples from late Quaternary marine assemblages of calcifying organisms. Bivalve mollusks dominated the data,

EnvironmentJuly 28, 2026

Geometry controls momentum flux in the sprinkler problem.

Hydro- and aero-mechanical devices convert fluid flows into useful motions, force, and power. The operating principles can involve subtle and poorly understood physics, as epitomized by open questions about systems that aspirate flows through curving tubular arms. Since its introduction by Mach and popularization by Feynman, the so-called reverse sprinkler problem has evoked many competing theories and fluid mechanical effects that have not to date been distinguished by experiments. Here we cond

EnvironmentJuly 28, 2026

Guanidine fuels rapid resurrection of desert cyanobacteria.

In desert ecosystems, microbial activity is driven by brief hydration pulses but is severely limited by persistent nutrient scarcity. Cyanobacteria serve as essential pioneer photoautotrophs, maintaining biogeochemical cycles and ecosystem stability in these arid landscapes. However, their ability to quickly reactivate after rehydration is critically restricted by nitrogen availability. Although the nitrogen demand can be met later by biological nitrogen fixation, it is ineffective and irrelevan

EnvironmentJuly 28, 2026

The unique Efg1 fungal virulence regulon in the catheterized bladder environment.

Urinary catheterization, a frequent procedure in hospitals, nursing homes, and other healthcare facilities, is a primary driver of nosocomial infections. The most common of these are catheter-associated urinary tract infections (CAUTIs), which often progress to severe complication, sepsis, and ultimately death. The fungus Candida albicans is a primary causative agent of CAUTIs; yet, its tissue-specific pathogenesis remains poorly understood, which complicates development of efficient treatments.