C & en reviews the coolest compounds in 2017

"Sulfur flower" blooms twice Source: C & en sulfurized halobenzene, also known as "sulfur flower" because of its molecular shape like sunflower It is the first all sulfur substituted polycyclic aromatic hydrocarbon and the second member of the new cyclic heterocyclic carbon sulfur compound "flowers of sulfur" The first member is octathiophene [8] cycloene synthesized more than ten years ago Chemists have long wanted to develop other members, including the simplest benzene persulfate, as cathode and other electrode materials for batteries A team led by Feng Xinliang of Dresden University of Technology and KlausM ü llen of Max Planck Institute of polymers in Germany created a new "flower of sulfur" (J Am Chem Soc 2017, DOI: 10.1021/jacs.6b12630) The birth of the "Star" molecule molecular Star source: chem – EUR J chemists designed this angular Pentagram star palladium complex this year Its unique feature is not only its interesting shape - the regular pentagon surrounded by isosceles trapezoid, but also the first five core self-assembled multi partition molecule containing two different non chelating ligands A typical self-assembled complex is composed of a metal and a group of ligands Most importantly, ligands are usually chelated, which means that each ligand binds to a metal through two or more atoms Dillip Kumar Chand of Indian Institute of Technology Madras and his colleagues believe that their star molecules can stimulate the synthesis of cellular molecular cages with potential applications in biomedicine (chem – EUR J 2017, DOI: 10.1002/chem.201702264) The more complex norbornane source: C & en nortricycleene triol source: C & en this year, two research teams completed the synthesis of a new challenging bridged polycyclic alkane, and constructed a complex norbornane derivative Among them, Marcel mayor from the University of Basel, Switzerland, led the team to prepare trinorbornane This symmetric saturated c11h16 molecule is composed of two norbornene units sharing a pair of adjacent edges, which happens to form a third subunit of norbornene Such methods can help to expand the total synthesis technology of natural products (chem Commun 2017, DOI: 10.1039 / c7cc06273g) On the other hand, the research team led by volodymyr kozel and G ü nter Haufe from the University of Minster in Germany has synthesized nortricycleestriol, which is the smallest molecule with triple molecular symmetry among known chiral polycyclic compounds Researchers are using pure nortricyclene enantiomers to prepare liquid crystals (angel Chem Int ed 2017, DOI: 10.1002/anie.201709279) Knitted molecular junction MolecularKnot source: Robert W.McGregor David A Leigh of University of Manchester in England interwoven three helices together to build the first braided molecular knot this year The new molecular knot with 192 atoms has 8 intersections, which is much more complex than the former molecular knot composed of two kinks The Leigh group first assembled the bipyridine ligands into braided structures by using the iron atoms Then, through the olefin metathesis reaction, the olefins at the end of the ligand are linked together, and the iron atoms and equilibrium ions are removed to form a continuous winding structure Researchers hope to create more complex braided molecular knots, or even braided polymers (Science 2017, DOI: 10.1126 / science Aal1619) Source of the missing heterocyclic dioxaazatriborinane: for many years, chemists have combined B, C, N, O atoms in different ways, thus creating a variety of six membered heterocyclic systems One of the goals is to construct new polycyclic aromatic compounds with electron deficient boron atoms, which can be used to make optoelectronic devices However, it is still unclear how to mix nitrogen, oxygen and boron into heterocycles at the same time A team led by masakatsu Shibasaki and Naoya Kumagai from Japan Institute of Microbial Chemistry designed and synthesized dioxazaborocyclohexane (b3no2), which is the missing ring in b3n3 and b3o3 The team found that dioxazaborocyclohexane can catalyze the amidation reaction, and the effect is better than the previously known boron containing organic catalytic machine (NAT Chem 2017, DOI: 10.1038 / nchem 2708) The largest and most complex source of abinogalactan: C & en broke the record of carbohydrate synthesis this year: ye Xinshan of Peking University and his colleagues synthesized a super large and super complex polysaccharide molecule, which is twice as large as any before This polysaccharide molecule, known as arabinogalactan, has 92 sugar units and is the basic component of the cell wall of Mycobacterium tuberculosis The synthesis of the polysaccharide was blocked by ethambutol Natural polysaccharides have different structural forms and low abundance, which make them difficult to be separated and developed as drug targets or vaccines The same challenge lies in the de novo synthesis of these polysaccharides In one pot reaction, ye Xinshan research group assembled a group of short polysaccharides into a galactan chain (blue) and two identical arabinogan chains (black); then, through the [31 + 31 + 30] glycosylation reaction, the three polysaccharide chains were combined into an arabinoglycan containing 92 monosaccharide units (NAT Commun 2017, DOI: 10.1038/ncomms14851) The unique electronic structure of triazolium Lewis acid source: C & en triazenylradical source: C & en chemists in this year added different ways of bonding of triazoles The electron rich n-center molecules can be used as Lewis bases to provide the bond between the electron pair and the receptor group Mark gandelman of the Israel Institute of technology and his team found that triazolium salt can change the activity of CO receptor, so that the N center can act as Lewis acid and receive electrons N-containing Lewis acid can be used as a frittered Lewis pairs (FLP) or other types of catalysts (j.am.chem.soc 2017, DOI: 10.1021/jacs.6b12360) On the other hand, Triazene radicals have been previously detected by spectroscopy and have been proved to be ligands of transition metal complexes But they are unstable and difficult to separate The research team led by Eunsung Lee of the Korean Institute of basic sciences and Puxiang University of science and technology found that N-heterocyclic carbene could be used as a stable substituent Triazene radicals were used as cathode materials for lithium-ion batteries (j.am.chem.soc 2017, DOI: 10.1021/jacs.7b08753).