Assessing Global Environmental Sustainability Via an Unsupervised Clustering Framework

The importance of sustainable development has risen in recent years due to the significant number of people affected by lack of access to essential resources as well as the need to prepare for and adapt to intensifying climate change and rapid urbanization. Modeling frameworks capable of effectively assessing and tracking sustainability lie at the heart of creating effective policies to address these issues. Conventional frameworks, such as the Environmental Performance Index (EPI), that support such policies often involve ranking countries based on a weighted sum of a number of relevant environmental metrics. However, the selection and weighing processes are often biased. Moreover, the ranking process fails to provide policymakers with possible avenues to improve their country’s environmental sustainability. This study aimed to address these gaps by proposing a novel data-driven framework to assess the environmental sustainability of countries objectively by leveraging unsupervised learning theory. Specifically, this framework harnesses a clustering technique known as Self-Organized Maps to group countries based on their characteristic environmental performance metrics and track progression in terms of shifts within clusters over time. The results support the hypothesis that the inconsistencies in the EPI calculation can lead to misrepresentations of the relative sustainability of countries over time. The proposed framework, which does not rely on ranking or data transformations, enables countries to make more informed decisions by identifying effective and specific pathways towards improving their environmental sustainability

3-Benzyl­sulfanyl-1H-1,2,4-triazol-5-amine

In the title mol­ecule, C9H10N4S, the dihedral angle between the benzene and triazole rings is 81.05 (5)°. In the crystal, N—H⋯N hydrogen bonds link the mol­ecules into infinite zigzag chains along [010]

5-(2-Methoxy­benz­yl)-4-(2-methoxy­phen­yl)-4H-1,2,4-triazol-3-ol

In the mol­ecule of the title compound, C17H17N3O3, the triazole ring is oriented at dihedral angles of 88.09 (3) and 83.72 (3)° with respect to the 2-methoxy­benzyl and 2-methoxy­phenyl rings, respectively. The dihedral angle between the 2-methoxy­benzyl and 2-methoxy­phenyl rings is 52.95 (3)°. In the crystal structure, inter­molecular N—H⋯O hydrogen bonds link the mol­ecules into centrosymmetric dimers. There is a π–π contact between the 2-methoxy­phenyl rings [centroid–centroid distance = 3.811 (3) Å]

4-(4-Methoxy­phen­yl)-3-[2-(2-methoxy­phen­yl)eth­yl]-1H-1,2,4-triazol-5(4H)-one

The title compound, C18H19N3O3, is a biologically active triazole derivative. The five-membered ring is oriented with respect to the six-membered rings at dihedral angles of 51.59 (4) and 61.37 (4)°. The crystal structure is stabilized by inter­molecular N—H⋯O hydrogen-bond inter­actions between centrosymmetrically related mol­ecules [the dihedral angle between the benzene rings is 47.44 (5)°]

4-(2-Methoxy­phenyl)-3-(3,4,5-tri­methoxy­phen­ethyl)-2H-1,2,4-triazole-5(4H)-thione

The title compound, C20H23N3O4S, is an important biologically active heterocyclic compound. The five-membered ring is oriented with respect to the six-membered rings at dihedral angles of 78.60 (3) (trimethoxyphenyl ring) and 71.57 (3)° (methoxyphenyl ring). In the crystal structure, inter­molecular N—H⋯O hydrogen bonds link the mol­ecules into infinite chains along the c axis

1-Phenyl-2-(1H-1,2,4-triazol-1-yl)ethanone

In the mol­ecule of the title compound, C10H9N3O, the triazole and phenyl rings are nearly perpendicular to each other, with a dihedral angle of 88.72 (4)°. In the crystal structure, inter­molecular C—H⋯O and C—H⋯N hydrogen bonds link the mol­ecules. There are C—H⋯π contacts between the 1,2,4-triazole rings, and between the phenyl and 1,2,4-triazole rings, and there is a weak π–π contact between the 1,2,4-triazole and phenyl rings [centroid-to-centroid distance = 4.547 (1) Å]

5-(3-Methoxy­pheneth­yl)-4-(2-methoxy­phen­yl)-4H-1,2,4-triazol-3-ol

In the mol­ecule of the title compound, C18H19N3O3, the triazole ring is oriented with respect to the 3-methoxy­phenyl and 2-methoxy­phenyl rings at dihedral angles of 11.79 (3) and 89.22 (3)°, respectively. The dihedral angle between the two benzene rings is 85.95 (3)°. In the crystal structure, inter­molecular O—H⋯N and C—H⋯O hydrogen bonds link the mol­ecules. There is a π–π contact between the triazole and 3-methoxy­phenyl rings [centroid–centroid distance = 3.916 (3) Å]. There is a π–π contact between the triazole and one of the 3-methoxy­phenyl rings [centroid–centroid distance = 3.916 (3) Å ]. C—H⋯π contacts are also found between the benzene ring and the methyl groups of their 3-methoxy-substituents

Intramolecular additions of various π-nucleophiles to chemoselectively activated amides and application to the synthesis of (±)-tashiromine

Abstract: Vilsmeier-Haack type cyclizations proved to be particularly efficient for generating parts of the polycyclic cores of many alkaloids, although only monocyclizations have so far been reported. With the goal of rapidly and efficiently constructing polycyclic alkaloids, we decided to exploit the Vilsmeier-Haack reaction by utilizing iminium ions successively generated and trapped with tethered nucleophiles. To develop such a strategy, we had to set the first cyclization. This constitutes a great challenge in itself because amide activation conditions are usually not compatible with tethered nucleophiles, except for indoles and aromatic rings which have already been reported. This paper describes the comprehensive study of intramolecular addition of silyl enol ethers, allylsilanes, and enamines to chemoselectively activated formamides, aliphatic amides, and lactams. Good to excellent yields were obtained for the 5-exo, 6-exo, and 6-endo modes of cyclization. Moreover, we demonstrated that the species in solution after the cyclization are iminium ions. This is highly encouraging for the development of bis-cyclization strategies. An expeditious total synthesis of (()-tashiromine is also reported

3-(3-Methoxy­benz­yl)-4-(2-methoxy­phen­yl)-1H-1,2,4-triazole-5(4H)-thione

In the title compound, C17H17N3O2S, the five-membered ring forms dihedral angles of 53.02 (3) and 78.57 (3)° with the 3-meth­oxy-substituted and 2-meth­oxy-substituted benzene rings, respectively. In the crystal structure, mol­ecules are linked into centrosymmetric dimers via inter­molecular N—H⋯S hydrogen bonds

1-[2-(2,6-Dichloro­benz­yloxy)-2-(2-fur­yl)eth­yl]-1H-1,2,4-triazole

In the mol­ecule of the title compound, C15H13Cl2N3O2, the triazole ring is oriented at dihedral angles of 2.54 (13) and 44.43 (12)°, respectively with respect to the furan and dichloro­benzene rings. The dihedral angle between the dichloro­benzene and furan rings is 46.75 (12)°. In the crystal structure, inter­molecular C—H⋯O hydrogen bonds link the mol­ecules into centrosymmetric dimers and π–π contacts between dichloro­benzene rings [centroid–centroid distance = 3.583 (2) Å] may further stabilize the structure. Inter­molecular C—H⋯π contacts between the triazole and furan rings also occur