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1. Indolylthio Glycosides As Effective Building Blocks for Chemical Glycosylation

   https://doi.org/10.1021/acs.joc.0c00943  

   Shrestha, Ganesh; Panza, Matteo; Singh, Yashapal; Rath, Nigam P.; Demchenko, Alexei V. (December 2020, The Journal of Organic Chemistry)

   null (Ed.)
2. Glycosyl nitrates in synthesis: streamlined access to glucopyranose building blocks differentiated at C-2

   https://doi.org/10.1039/c8ob00477c  

   Wang, Tinghua; Nigudkar, Swati S.; Yasomanee, Jagodige P.; Rath, Nigam P.; Stine, Keith J.; Demchenko, Alexei V. (January 2018, Organic & Biomolecular Chemistry)

   null (Ed.)

   In an attempt to refine a CAN-mediated synthesis of 1,3,4,6-tetra- O -acetyl-α- d -glucopyranose (2-OH glucose) we unexpectedly discovered that this reaction proceeds via the intermediacy of glycosyl nitrates. Improved mechanistic understanding of this reaction led to the development of a more versatile synthesis of 2-OH glucose from a variety of precursors. Also demonstrated is the conversion of 2-OH glucose into a variety of building blocks differentially protected at C-2, a position that is generally hard to protect regioselectively in the glucopyranose series. 

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3. (Phosphanyl)phosphaketenes as building blocks for novel phosphorus heterocycles

   https://doi.org/10.1039/C7SC00300E  

   Hansmann, Max M.; Ruiz, David A.; Liu, Liu; Jazzar, Rodolphe; Bertrand, Guy (January 2017, Chemical Science)

   Although BH 3 simply coordinates the endocyclic P of (phospholidino)phosphaketene 1Dipp , the bulkier B(C 6 F 5 ) 3 gives rise to a zwitterionic diphosphirenium, which is a novel type of 2π-electron aromatic system as shown by the calculated NICS values. While the reaction of 1Dipp with Na[PCO(dioxane) x ] is unselective, the same reaction with the sterically bulky (phospholidino)phosphaketene 1Ar** [Ar** = 2,6-bis[di(4- tert -butylphenyl)methyl]-4-methylphenyl selectively affords a sodium bridged dimer containing a hitherto unknown λ 3 ,λ 5 ,λ 3 -triphosphete core. The latter formally results from “P − ” addition to a 1,3-P/C-dipole. Similarly, adamantyl isonitrile adds to 1Dipp giving a 4-membered phosphacycle. In contrast to 1 , the phosphaketene derived from the electrophilic diazaphospholidine-4,5-dione is unstable and reacts with a second molecule of Na[PCO(dioxane) x ] to afford a 1,3,4-oxadiphospholonide derivative. 

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4. Scutoids as Building Blocks for Topologically Interlocking Material Systems

   https://doi.org/10.1002/adem.202400270  

   Ballance, Tanner; Siegmund, Thomas (April 2024, Advanced Engineering Materials)

   Topologically interlocking material (TIM) systems are constrained assemblies of building blocks with geometry such that individual unit elements cannot be removed from the assembly without complete disassembly. These assemblies can bear load in the absence of adhesive bonds. TIM systems with scutoid‐shaped building blocks are investigated. Scutoids are prism‐like shapes with two polygonal faces and contain vertices on the lateral sides which enable geometric interlocking. The quasi‐static mechanical behavior of two types of scutoid‐based TIM systems is investigated and compared to reference tetrahedron‐based TIM systems. TIM systems are realized as plate‐type assemblies and a central point‐force load is considered. The computational analysis is conducted with the finite‐element method. Scutoid‐based TIM systems are found, in aggregate, to match or exceed the performance of the tetrahedra‐based systems. It is documented that TIM systems in general, but scutoid‐based systems in particular, emerge to possess chiral characteristics. The combination of building block symmetry and assembly symmetry together determines the type of chirality in the mechanical response. Experimental data validates the computational finding. In summary, considering scutoids as building blocks for load‐carrying TIM assemblies opens the pathway to new classes of mechanical behavior in systems where structure and microstructure strongly interact with each other. 

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5. Clickable PEG hydrogel microspheres as building blocks for 3D bioprinting

   https://doi.org/10.1039/C8BM01286E  

   Xin, Shangjing; Chimene, David; Garza, Jay E.; Gaharwar, Akhilesh K.; Alge, Daniel L. (February 2019, Biomaterials Science)

   Three-dimensional (3D) bioprinting is important in the development of complex tissue structures for tissue engineering and regenerative medicine. However, the materials used for bioprinting, referred to as bioinks, must have a balance between a high viscosity for rapid solidification after extrusion and low shear force for cytocompatibility, which is difficult to achieve. Here, a novel bioink consisting of poly(ethylene glycol) (PEG) microgels prepared via off-stoichiometry thiol–ene click chemistry is introduced. Importantly, the microgel bioink is easily extruded, exhibits excellent stability after printing due to interparticle adhesion forces, and can be photochemically annealed with a second thiol–ene click reaction to confer long-term stability to printed constructs. The modularity of the bioink is also an advantage, as the PEG microgels have highly tunable physicochemical properties. The low force required for extrusion and cytocompatibility of the thiol–ene annealing reaction also permit cell incorporation during printing with high viability, and cells are able to spread and proliferate in the interstitial spaces between the microgels after the constructs have been annealed. Overall, these results indicate that our microgel bioink is a promising and versatile platform that could be leveraged for bioprinting and regenerative manufacturing. 

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