Condensation of 2,5-diethoxyterephthalohydrazide with 1,3,5-triformylbenzene or 1,3,5-tris(4-formylphenyl)benzene yields two new covalent organic frameworks, COF-42 and COF-43, in which the organic building units are linked through hydrazone bonds to form extended two-dimensional porous frameworks. Both materials are highly crystalline, display excellent chemical and thermal stability, and are permanently porous. These new COFs expand the scope of possibilities for this emerging class of porous materials.

Chemical modifications of native proteins can facilitate production of supernatural protein functions that are not easily accessible by complementary methods relying on genetic manipulations. However, accomplishing precise control over selectivity while maintaining structural integrity and homogeneity still represents a formidable challenge. Herein, we report a transition metal-free method for tryptophan-selective bioconjugation of proteins that is based on an organoradical and operates under ambient conditions. This method exhibits low levels of cross-reactivity and leaves higher-order structures of the protein and various functional groups therein unaffected. The strategy to target less abundant amino acids contributes to the formation of structurally homogeneous conjugates, which may even be suitable for protein crystallography. The absence of toxic metals and biochemically incompatible conditions allows a rapid functional modulation of native proteins such as antibodies and pathogenic aggregative proteins, and this method may thus easily find therapeutic applications.

A procedure for making covalently linked organometallic complexes within the pores of metal-organic frameworks (MOFs) has been described. An N-heterocyclic carbene precursor containing link L0 was prepared and then constructed into a MOF-5-type structure (IRMOF-76). Attempts to produce covalently bound organometallic complexes in IRMOF-76 were unsuccessful. An alternative way of linking the first metalated link, L1, into the desired metalated MOF structure, IRMOF-77, was successful. IRMOF-76 and -77 were characterized by single-crystal X-ray studies. Demonstration of permanent porosity and successful substitution of the pyridine coligand in IRMOF-77 are also described.

A general catalytic allylation of simple ketoimines was developed using 1 mol % of CuF.3PPh(3) as catalyst, 1.5 mol % of La(O(i)Pr)(3) as the cocatalyst, and stable and nontoxic allylboronic acid pinacol ester as the nucleophile. This reaction constituted a good template for developing the first catalytic enantioselective allylation of ketoimines. In this case, using LiO(i)Pr as the cocatalyst produced higher enantioselectivity and reactivity than La(O(i)Pr)(3). Thus, using the CuF-cyclopentyl-DuPHOS complex (10 mol %) and LiO(i)Pr (30 mol %) in the presence of (t)BuOH (1 equiv) produced high enantioselectivity up to 93% ee from a range of aromatic ketoimines. Mechanistic studies indicated that LiO(i)Pr accelerates the reaction by increasing the concentration of an active nucleophile, allylcopper.