The first rhodium(II)-catalyzed aza-[4+3] cycloadditions of 1-sulfonyl 1,2,3-triazoles with 1,3-dienes have been developed, and enable the efficient synthesis of highly functionalized 2,5-dihydroazepines from readily available precursors. In some cases, the reaction pathway could divert to formal aza-[3+2] cycloadditions, thus leading to 2,3-dihydropyrroles. In this context, the titled reaction represents a capable tool for the divergent synthesis of two types of synthetically valuable aza-heterocycles from common rhodium(II) iminocarbene intermediates.

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Based on green chemistry, a simple and efficient direct synthesis of 4‐(4′‐hydroxyaryl)(2H)phthalazin‐1‐ones (2a–2f) was developed in a two‐step reaction, in which the Friedel–Crafts acylation reaction of six phenols with phthalic anhydride was initially carried out and then followed by cyclization with hydrazine hydrate in good to excellent yields with high regioselectivity. A number of novel heterocyclic poly(arylene ether ketone)s were prepared conveniently from several unsymmetrical, twist, and noncoplanar phthalazinone‐containing monomers (2a–2f) and an activated difluoro monomer via a NC coupling reaction. It was very interesting that the obtained monomers and polymers exhibited diverse properties with the variation of the number and location of the substituted methyl groups. All these polymers had a high molecular weight with Mn and ηinh in the range of 44,960–169,000 Da and 0.38–0.79 dL/g, respectively. Actually, the obtained polymers displayed excellent thermal properties with Tg's ranging from 222 to 248 °C and 5% weight loss temperatures in nitrogen higher than 430 °C. Moreover, these polymers were readily soluble in common organic solvents, such as N‐methyl‐2‐pyrrolidone, chloroform, pyridine, and m‐cresol, and could be cast into flexible and colorless or nearly colorless films by spin‐coating or casting processes. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1525–1535, 2007

The first rhodium(II)-catalyzed aza-[4+3] cycloadditions of 1-sulfonyl 1,2,3-triazoles with 1,3-dienes have been developed, and enable the efficient synthesis of highly functionalized 2,5-dihydroazepines from readily available precursors. In some cases, the reaction pathway could divert to formal aza-[3+2] cycloadditions, thus leading to 2,3dihydropyrroles. In this context, the titled reaction represents a capable tool for the divergent synthesis of two types of synthetically valuable aza-heterocycles from common rhodium(II) iminocarbene intermediates.

An enantioselective synthesis of (+)-8-epi-xanthatin hinging on a chiral phosphoric acid catalyzed tandem allylboration/lactonization reaction is reported. With (+)-8-epi-xanthatin as the precursor, the collective synthesis of a series of synthetically challenging xanthanolides was also accomplished. Among them, xanthipungolide, one of the most complex xanthanolide monomers, was accessed through a bioinspired tandem double-bond isomerization/6π electronic cyclization/intramolecular Diels-Alder reaction, and pungiolides A, B, D, E, and L-N, a group of xanthanolide dimers, were assembled through a bioinspired Diels-Alder dimerization followed by late-stage diversification.

A new [3 + 4] cycloaddition of azaoxyallyl cations and anthranils has been achieved for rapid access to multisubstituted benzodiazepine derivatives. A variety of anthranils and α-halo hydroxamates were both effective substrates with simple operations under transition-metal-free conditions. The intriguing features of this method include its mild nature of the reaction conditions, high efficiency, broad substrate scope, and wide functional group compatibility.N itrogen heterocycles are widespread structural motifs in bioactive natural products, therapeutic agents, agrochemicals, and material molecules with significant activities. 1 In particular, benzodiazepines, a member of the family of privileged scaffold, occupy a significant place in pharmaceutical ingredients. 2 As representative examples shown in Figure 1, SB-214857 (lotrafiban), a potent glycoprotein IIb/IIIa receptor antagonist, displays antithrombotic activity. 3 Diazepam, commercially known as Valium, is used to treat anxiety. 2a Abbemycin, isolated from Streptomyces sp. AB-999F-52, is an antibiotic. 4 TRAIL (tumor necrosis factor-related apoptosisinducing ligand)-resistance could be overcome by use of fuligocandin B. 5 Circumdatin D and E are two quinazolinobenzodiazepine alkaloids isolated from the fungus Aspergillus ochraceus. 6 Given the rich biological profiles of the sevenmembered nitrogen heterocycles in organic synthesis and medical chemistry, the development of a novel method to access benzodiazepine and related scaffolds remains highly desirable.[3 + 4]-Cycloaddition reaction is an efficient strategy to assemble seven-membered rings. 7 In recent years, azaoxyallyl

Word embedding has become essential for natural language processing as it boosts empirical performances of various tasks. However, recent research discovers that gender bias is incorporated in neural word embeddings, and downstream tasks that rely on these biased word vectors also produce gender-biased results. While some word-embedding gender-debiasing methods have been developed, these methods mainly focus on reducing gender bias associated with gender direction and fail to reduce the gender bias presented in word embedding relations. In this paper, we design a causal and simple approach for mitigating gender bias in word vector relation by utilizing the statistical dependency between gender-definition word embeddings and gender-biased word embeddings. Our method attains state-of-the-art results on gender-debiasing tasks, lexical- and sentence-level evaluation tasks, and downstream coreference resolution tasks.

A formal synthesis of cephalotaxine, the parent member of the Cephalotaxus alkaloids, was achieved. It features a practical four-step assembly of the benzazepine-bearing pentacyclic ring system through two alkylation reactions, acidic hydrolysis, and aldolization.