More Like this

1. An organocascade approach to α,α-chlorofluoroalcohols

   https://doi.org/10.1016/j.tetlet.2015.05.107  

   Hayes, Montgomery D.; Rodríguez-Alvarado, Melanie; Brenner-Moyer, Stacey E. (August 2015, Tetrahedron Letters)
2. Deoxygenative α-alkylation and α-arylation of 1,2-dicarbonyls

   https://doi.org/10.1039/d0sc03118f  

   Jin, Shengfei; Dang, Hang T.; Haug, Graham C.; Nguyen, Viet D.; Arman, Hadi D.; Larionov, Oleg V. (September 2020, Chemical Science)

   null (Ed.)

   Construction of C–C bonds at the α-carbon is a challenging but synthetically indispensable approach to α-branched carbonyl motifs that are widely represented among drugs, natural products, and synthetic intermediates. Here, we describe a simple approach to generation of boron enolates in the absence of strong bases that allows for introduction of both α-alkyl and α-aryl groups in a reaction of readily accessible 1,2-dicarbonyls and organoboranes. Obviation of unselective, strongly basic and nucleophilic reagents permits carrying out the reaction in the presence of electrophiles that intercept the intermediate boron enolates, resulting in two new α-C–C bonds in a tricomponent process. 

   more » « less
3. Lipidated α/α-AA heterogeneous peptides as antimicrobial agents

   https://doi.org/10.1016/j.ejmech.2018.06.006  

   Singh, Sylvia; Nimmagadda, Alekhya; Su, Ma; Wang, Minghui; Teng, Peng; Cai, Jianfeng (July 2018, European Journal of Medicinal Chemistry)
4. Polynomial α-attractors

   https://doi.org/10.1088/1475-7516/2022/04/017  

   Kallosh, Renata; Linde, Andrei (April 2022, Journal of Cosmology and Astroparticle Physics)

   Abstract Inflationary α -attractor models can be naturally implemented in supergravity with hyperbolic geometry. They have stable predictions for observables, such as n s = 1 - 2/ N e , assuming that the potential in terms of the original geometric variables, as well as its derivatives, are not singular at the boundary of the hyperbolic disk, or half-plane. In these models, the potential in the canonically normalized inflaton field φ has a plateau, which is approached exponentially fast at large φ . We call them exponential α-attractors . We present a closely related class of models, where the potential is not singular, but its derivative is singular at the boundary. The resulting inflaton potential is also a plateau potential, but it approaches the plateau polynomially. We call them polynomial α-attractors . Predictions of these two families of attractors completely cover the sweet spot of the Planck/BICEP/Keck data. The exponential ones are on the left, the polynomial are on the right. 

   more » « less
5. On the α-q-Mutual Information and the α-q-Capacities

   https://doi.org/10.3390/e23060702  

   Ilić, Velimir M.; Djordjević, Ivan B. (June 2021, Entropy)

   null (Ed.)

   The measures of information transfer which correspond to non-additive entropies have intensively been studied in previous decades. The majority of the work includes the ones belonging to the Sharma–Mittal entropy class, such as the Rényi, the Tsallis, the Landsberg–Vedral and the Gaussian entropies. All of the considerations follow the same approach, mimicking some of the various and mutually equivalent definitions of Shannon information measures, and the information transfer is quantified by an appropriately defined measure of mutual information, while the maximal information transfer is considered as a generalized channel capacity. However, all of the previous approaches fail to satisfy at least one of the ineluctable properties which a measure of (maximal) information transfer should satisfy, leading to counterintuitive conclusions and predicting nonphysical behavior even in the case of very simple communication channels. This paper fills the gap by proposing two parameter measures named the α-q-mutual information and the α-q-capacity. In addition to standard Shannon approaches, special cases of these measures include the α-mutual information and the α-capacity, which are well established in the information theory literature as measures of additive Rényi information transfer, while the cases of the Tsallis, the Landsberg–Vedral and the Gaussian entropies can also be accessed by special choices of the parameters α and q. It is shown that, unlike the previous definition, the α-q-mutual information and the α-q-capacity satisfy the set of properties, which are stated as axioms, by which they reduce to zero in the case of totally destructive channels and to the (maximal) input Sharma–Mittal entropy in the case of perfect transmission, which is consistent with the maximum likelihood detection error. In addition, they are non-negative and less than or equal to the input and the output Sharma–Mittal entropies, in general. Thus, unlike the previous approaches, the proposed (maximal) information transfer measures do not manifest nonphysical behaviors such as sub-capacitance or super-capacitance, which could qualify them as appropriate measures of the Sharma–Mittal information transfer. 

   more » « less