A series of non-hydroxylic crystalline host compounds, [4 + 2]Ï cycloadducts of phencyclone and N-arylmaleimides having a bicyclo[2.2.1]heptene-7-one system, was synthesized and their inclusion behavior investigated. X-Ray crystal analyses of the inclusion compounds of the N-(1-naphthyl) derivative with butan-2-one, the N-(m-tolyl) derivative with p-xylene, together with the guest-free host and the N-(p-tolyl) derivative with m-xylene indicate that the âspaceâ surrounded by the phenanthrene ring, two phenyl rings and bridge carbonyl of the 1,3-diphenyl-1,3-dihydrocyclopenta[l]phenanthren-2-one moiety plays an important role, not only in the formation of inclusion complexes with the aromatic guests but also in hostâhost interactions. In every case, the N-aryl succinimide assists complex formation with the guests, in which the weak lattice forces due to CâHâ¯Ï
and CâHâ¯O interactions are operative. Methyl-substituted benzenes are effectively recognized by the CâHâ¯Ï interactions between the guest molecules and the phenanthrene ring of the hosts.
e with S-allyl S-methyl dithiocarbonate gave the endo cycloadduct whereas phencyclone gave a mixture of the endo and exo cycloadducts. The X-ray analysis of the cycloadduct of phencyclone and S-allyl S-methyl dithiocarbonate indicated the presence of a short contact of Ar–H···OC< type. A possible role of the interaction in determining the endo/exo selectivity was discussed based on the X-ray crystallographic
dissected halogen–aryl π interactions experimentally using a bicyclic N-arylimide based moleculartorsionbalances system, which is based on the influence of the non-bonded interaction on the equilibria between folded and unfolded states. Through comparison of balances modulated by higher halogens with fluorinebalances, we determined the magnitude of the halogen–aryl π interactions in our unimolecular
Diels–Alder Reaction of Isobenzofurans/Cyclopentadienones with Tetrathiafulvalene: Preparation of Naphthalene, Fluoranthene, and Fluorenone Derivatives
作者:Jayachandran Karunakaran、Arasambattu K. Mohanakrishnan
DOI:10.1021/acs.orglett.7b03686
日期:2018.2.16
Diels–Alder reaction of 1,3-diarylbenzo[c]furan/cyclopentadienone with TTF followed by triflic acid mediated cleavage of the resulting adducts led to the formation of the respective 1,4-diaryl substituted naphthalenes, fluoranthenes, and fluorenones. The photophysical properties of representative diaryl-substituted hydrocarbons are also reported.
1,3-二芳基苯并[ c ]呋喃/环戊二烯酮与TTF的Diels-Alder反应,然后由三氟乙酸介导裂解所生成的加合物,从而形成各自的1,4-二芳基取代的萘,荧蒽和芴酮。还报道了代表性的二芳基取代的烃的光物理性质。
Tipping the Balance between S-π and O-π Interactions
作者:Jungwun Hwang、Ping Li、Mark D. Smith、Constance E. Warden、Dominic A. Sirianni、Erik C. Vik、Josef M. Maier、Christopher J. Yehl、C. David Sherrill、Ken D. Shimizu
DOI:10.1021/jacs.8b07617
日期:2018.10.17
comprehensive experimental survey consisting of 36 molecular balances was conducted to compare 18 pairs of S-π versus O-π interactions over a wide range of structural, geometric, and solvent parameters. A strong linear correlation was observed between the folding energies of the sulfur and oxygen balances across the entire library of balance pairs. The more stable interaction systematically switched