Keywords: Azulene / Borylation / CϪH activation / IridiumThe 4,4,5,5-tetramethyl-1,3,2-dioxaborolanyl group was directly introduced into the 2-positions of azulenes with high selectivity by the C−H activation method with use of iridium catalysis.

Chiral chlorobismuthines 3 stabilized by intramolecular coordination of an N,N-dimethylamino group have been synthesized by the selective fluorodearylation of the bismuthines 1 with boron trifluoride-diethyl ether, followed by halogen exchange of the resulting fluorobismuthines 2 with brine. An X-ray crystallographic structure analysis of 3b revealed that the bismuth centre has a distorted pseudotrigonal bipyramidal structure through the formation of a hypervalent 3-centre 4-electron bond with the chlorine and nitrogen atoms at apical positions. 'H NMR spectra of compounds 3 in CDCI, at room temperature reflected their fixed conformation in the solid state.Chiral chlorobismuthines 7a and 7b were obtained in a similar manner starting from optically pure (R)-N,N-dimethyl-I -phenylethylamine as a mixture of two diastereoisomers (77: 23 and 78: 22, respectively), the isomeric ratios of which were not influenced by the equatorial aryl groups present. Variable-temperature dynamic 'H NM R spectra of the diastereoisomeric mixture of 7a provided important information about its behaviour in solution; in [*H,]toluene dynamic but reversible dissociation of intramolecular Bi-N coordination was observed only at elevated temperatures, while in [2H6]-DMS0 it occurred quite easily below room temperature, leading to the inversion of configuration at the chiral bismuth centre.7 This functional group was previously employed for the synthesis of diastereoisomeric five-coordinated organosilicons and organotin halides 5c with a chiral metal centre.

The catalytic introduction of an allyl group at nonacidic C(sp)-H bonds was achieved under photoirradiation, in which 1,2-bis(phenylsulfonyl)-2-propene acts as an allyl source and 5,7,12,14-pentacenetetrone (PT) works as a C-H bond-cleaving catalyst. A variety of substances, including alkanes, carbamates, ethers, sulfides, and alcohols, were chemoselectively allylated in a single step under neutral conditions. The present transformation is catalyzed solely by an organic molecule, PT, and proceeds smoothly even under visible light irradiation (425 nm) in the case of alkanes as a starting substance.

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Dithienobismoles having a bismole ring fused with a bithiophene system were prepared by the reactions of β,β′-dilithiobithiophenes with aryldihalobismuthanes, as novel phosphorescence materials.