Droplet
deposition on superhydrophobic surfaces has been a great challenge
owing to the shortness of the impact contact time. Despite recent
research progress regarding flat superhydrophobic surfaces, improving
deposition on ubiquitous wired and curved superhydrophobic leaves
remains challenging as their surface structures promote asymmetric
impacts, thereby shortening the contact times and increasing the likelihood
of droplet splitting. Here, we propose a strategy to solve the deposition
problems based on an analysis of the impact dynamics and a rational
selection of additives. Combining the prominent extension property
of flexible polymers with surface tension reduction of the surfactant,
the well-chosen binary additives cooperatively solve retention and
coverage problems by limiting the fragment and enhancing local pinning
and wetting processes at a very low usage. This work advances the
understanding of droplet deposition by rationally selecting additives
based on the impact dynamics, which is believed to be useful in a
variety of spraying, coating, and printing applications.
In this paper we describe the phosphine-catalyzed [3 + 2], [3 + 3], [4 + 3], and [3 + 2 + 3] annulations of azomethine imines and allenoates. These processes mark the first use of azomethine imines in nucleophilic phosphine catalysis, producing dinitrogen-fused heterocycles, including tetrahydropyrazolo-pyrazolones, -pyridazinones, -diazepinones, and -diazocinones. Counting the two different reaction modes in the [3 + 3] cyclizations, there are five distinct reaction pathways—the choice of which depends on the structure and chemical properties of the allenoate. All reactions are operationally simple and proceed smoothly under mild reaction conditions, affording a broad range of 1,2-dinitrogen–containing heterocycles in moderate to excellent yields. A zwitterionic intermediate formed from a phosphine and two molecules of ethyl 2,3-butadienoate acted as a 1,5-dipole in the annulations of azomethine imines, leading to the [3 + 2 + 3] tetrahydropyrazolodiazocinone products. The incorporation of two molecules of an allenoate into an eight-membered-ring product represents a new application of this versatile class of molecules in nucleophilic phosphine catalysis. The salient features of this protocol—the facile access to a diverse range of nitrogen-containing heterocycles and the simple preparation of azomethine imine substrates—suggest that it might find extensive applications in heterocycle synthesis.
An iridium photoredox catalyst in combination with phenanthroline-supported palladium catalyst catalyzes decarboxylative alkenylation of tertiary and secondary aliphatic carboxylic acids with vinyl arenes to deliver β-alkylated styrenes with Z-selectivity. A broad scope of aliphatic carboxylic acids, including amino acids, exhibit as amenable substrates, and external oxidant is not required. The reaction proceeds by synergistic utilization of both energy-transfer and electron-transfer reactivity of iridium photoredox catalyst merging with palladium-catalyzed hydride elimination and insertion.
Phasmatodea represents an order of hemimetabolous insects. This group includes species with extreme forms of masquerade crypsis, whereby they imitate twigs, bark, lichen, moss, and leaves. In this study, we sequenced and annotated three mitochondrial genomes (mitogenomes) from Phasmatodea. The lengths of the novel mitogenomes range from 14,162 bp to 15,879 bp. The gene content and organization correspond to those inferred for the ancestral insect. We conducted phylogenetic analyses together with the existing mitogenomes of polyneopterans and mayflies. In most cases, the Phasmatodea was non-monophyletic, with Embioptera and Zoraptera nested inside. The mitogenome sequences from Embioptera and Zoraptera suffered from high substitution rates and displayed very long branches in phylogenetic trees. The monophyletic Phasmatodea was recovered only when the analysis employed the site-heterogeneous CAT-GTR model in PhyloBayes and used the nucleotide dataset PCG_nt. The Euphasmatodea was well established by various data types and inference methods. In addition, the clade Heteropterygidae and the subfamilies Lonchodinae and Necrosciinae were strongly supported. The Australasian clade Lanceocercata was recovered across analyses. However, the Clitumninae was non-monophyletic.
Phosphine-catalyzed [3+2] and [4+3]annulation reactions of C,N-cyclic azomethine imines with allenoates have been developed to give a variety of pharmaceutically attractive tetrahydroisoquinoline derivatives in moderate to excellent yields. The two distinct reaction pathways, [3+2] and [4+3]cyclization, depend on the nature of the nucleophilic phosphine and the allenoate. Generally, for α-alkylallenoates, the reactions always proceed with [3 +2]cyclization as the major pathway no matter what phosphine was used; for α-ArCH2-substituted allenoates, the reaction pathway was controlled by the phosphine catalyst used.
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