The first (O-I-N) carbonyl hypoiodites have been synthesised based on trimesic acid and pyridine or 4-methylpyridine, with their structures definitively confirmed by single crystal X-ray diffraction (SCXRD). The more soluble carbonyl hypoiodites based on pivalic acid have also been studied NMR, SCXRD, and computational analyses, enabling the study of the direct silver(I) precursor and intermediates of the resulting carbonyl hypoiodites generated using a range of substituted pyridines.
View Article and Find Full Text PDFAn asymmetric Michael addition of malononitrile to vinyl phosphonates was accomplished by hydrogen bond-enhanced bifunctional halogen bond (XB) catalysis. NMR titration experiments were used to demonstrate that halogen bonding, with the support of hydrogen-bonding, played a key role in the activation of the Michael acceptors through the phosphonate group. This is the first example of the use of XBs for the activation of organophosphorus compounds in synthesis.
View Article and Find Full Text PDFAn efficient enantioselective organocatalytic method for the synthesis of -alkylated indoles with α-branched alkyl substituents from the corresponding unsaturated indolyl ketones via a Michael addition has been developed. The resulting products were obtained in high enantioselectivities and in good yields. Various nucleophiles (nitroalkanes, malononitrile, malonic esters) can be used.
View Article and Find Full Text PDFChiral cyclohexanohemicucurbit[n]urils (n = 6, 8) (cycHCs) are able to bind guests through multiple "outer surface interactions", which in the case of planar zinc porphyrins leads to induction of chirality. Crystal structures of complexes of complementary sized hosts revealed social self-sorting, while in the solution phase one cycHC can accommodate up to three porphyrin molecules with log Ktotal 9.
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