[reaction: see text]. The copper iodide-catalyzed cross-coupling of terminal alkynes with hypervalent iodonium salts was accomplished with CuI (10 mol %) and NaHCO3 (2 equiv) in DME/H2O (4:1) at room temperature for 30 min to afford arylalkynes or enynes under mild conditions.

A new small-molecular thermally cross-linkable material {[4-(9-phenyl-9H-carbazol-4-yl)phenyl]-bis-(4′-vinylbiphenyl-4-yl)-amine} (PCP-bis-VBPA, PbV) containing the styrene moiety was synthesized for hole transport layers in wet processed organic light-emitting diodes (OLEDs). It was found that PbV exhibited relatively high glass temperatures above 154 °C and a triplet energy (T 1 ) greater than 2.81 eV. This new synthetic hole transport material (HTM) forms very uniform films after crosslinking reaction with little pin-holes, although it was smallmolecule-based cross-linkable HTM. However, to solve the certain minor non-uniformity caused by pinholes with various sizes, a semi-interpenetrating network was formed with well-known polymeric HTM with high mobility [e.g., poly(9,9-dioctylfluorene-co-N-(4-butylphenyl)diphenyl amine), TFB, or poly(N,N′-bis-4-butylphenyl-N,N′-bisphenyl)benzidine, poly-TPD]. As a result, we successfully fabricated red phosphorescent OLED showing an efficiency of about 16.7 cd/A and 12.4% (external quantum efficiency) if we applied PbV blended with 20% of TFB or poly-TPD. In particular, the efficiency and lifetime are significantly improved by 1.5 and 4.5 times, respectively, compared to those of the control device without using blended HTM.

[reaction: see text] A new protocol for the sequential allylic transfer reaction of a diene with two aldehydes in the construction of cyclic systems containing four stereogenic centers is achieved in a one-pot operation. Reaction of the diene-alehyde 1 with aldehyde in the presence of the diboronyl reagent catalyzed by a nickel complex produces products 2 and 3 depending on reaction conditions in high levels of diastereoselectivity. Extension of this method to the synthesis of six-membered rings is also investigated.

Diastereoselective germastannylation of bis(allenes) with germylstannanes, catalyzed by palladium complexes, for the construction of cis or trans five‐membered cyclic systems has been investigated. We observed that the relative stereochemical arrangements of the reaction products depends on the substituents in the reagents containing Ge−Sn σ‐bonds. When the reagent Ph3GeSnBu3 was employed in the Pd0‐catalyzed carbocyclization of bis(allenes), trans‐cyclized products and/or cis‐fused bicyclic dienes were produced. In contrast, cis cyclic compounds were obtained, again along with cis‐fused bicyclic dienes, from the reaction with Bu3GeSnBu3. NMR experiments to establish the stereochemical relationships and a mechanistic speculation for this transformation as a possible explanation for the different stereochemical outcomes are also described. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

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