Radical reactions initiated by the photochemical cleavage of carbon-indium bonds of organoindium compounds

Intra- and intermolecular reactions of carbon-centered radicals generated by photolysis of organoindium compounds were examined. The photolysis of vinylindium compounds and indium acetylides provided vinyl and alkynyl radicals, respectively, which were trapped with ethyl iodoacetate giving the corresponding β,γ-unsaturated esters. Allylic indium compounds, prepared from 8-bromo- or 8-iodooct-1,6-dienes and powdered indium metal, underwent an intramolecular radical cyclization to afford the 5-exo-trig product.     

Synthesis of new tricyclic mesoionic amides via photochemical conversion of a 5‐azido‐1‐mesityl‐3‐phenyltetrazolium salt

New mesoionic amides 4 and 5 with novel tricyclic ring systems have been synthesized by the photolysis of a 5‐azido‐1‐mesityl‐3‐phenyltetrazolium salt 1c via the corresponding triplet nitrene inter mediate. The structure of 5 has been determined by X‐ray crystallography.     

Risks of Muscle Atrophy in Patients with Malignant Lymphoma after Autologous Stem Cell Transplantation

Objective: Muscle atrophy is associated with autologous stem cell transplantation (ASCT)-related outcomes in patients with malignant lymphoma (ML). However, the impact of ASCT on muscle mass remains unclear in patients with ML. The aims of this study were to investigate changes in muscle mass and risk profiles for muscle atrophy after ASCT. Method: We enrolled 40 patients with refractory ML (age 58 [20-74] years, female/male 16/24, body mass index (BMI) 21.1 kg/m² [17.1-29.6]). Psoas muscle mass was assessed using the psoas muscle index (PMI) before and after ASCT. Statistical analysis used: Independent factors associated with a severe decrease rate of change in PMI were evaluated by decision-tree analysis, respectively. Results: PMI was significantly decreased after ASCT (4.61 vs. 4.55 cm²/m²; P=0.0425). According to the decision-tree analysis, the regimen was selected as the initial split. The rates of change in PMI were −5.57% and −3.97% for patients administered MCEC and LEED, respectively. In patients who were administered LEED, the second branching factor was BMI. In patients with BMI < 20.3 kg/m², the rate of change in PMI was −7.16%. On the other hand, the rate of change in PMI was 4.05% for patients with BMI ≥ 20.3 kg/m². Conclusion: We demonstrated that muscle mass decreased after ASCT in patients with ML. Patients who received MCEC and patients with low BMI were at risk for a decrease in muscle mass.     

Allylic-type diindium reagents. Reactivity toward electrophiles and cascade coupling reactions with imines

The allylic-type diindium reagents A and B were prepared from 3-bromo-1-iodopropene (1a) and 4-bromo-2-iodobut-2-ene (1b), respectively, and their reactions with electrophiles were investigated. The diindium reagents A and B were initially reacted with imines and the resulting vinylindium compounds were then treated with organic halides in the presence of Pd(PPh(3))(4) to give linear N-aryl and N-tosyl homoallylic amines. Diindium A is stable in a small amount of water in solvent, whereas B is easily protonated to give a crotylindium reagent. The reaction of B with benzaldehyde gives mainly the 1,3- and 1,5-diols via a spontaneous coupling with two molecules of the aldehyde, in contrast to A, which reacts with one molecule of carbonyl compounds to give the vinylindium compounds.     

Enhanced molecular fluorescence near thick Ag island film of large pseudotabular nanoparticles

A highly reflective thick Ag island film (TAIF) sputter-grown on mica, consisting of unique large pseudotabular nanoislands, 60-200 nm across and 30-60 nm thick, produced an unusually strong surface enhanced fluorescence (SEF) for rhodamine dyes situated very close to (only approximately 10 A away from) the metal surface. A significantly greater part of the enhanced fluorescence was emitted into the back half space through TAIF and the mica substrate. The detailed fluorescence angular distribution was very similar to that of the light scattering by TAIF, suggesting that the enhanced emission originated from some large induced dipoles in TAIF. For reference, we also present a quantitative analysis of the fluorescent behavior of the same dye but directly coated on a reference glass surface. TAIF showed no distinct dipolar surface plasmon-like bands for excitation at normal incidence, and the light absorption by dye-coated TAIF could be described by simple superposition of the contribution of TAIF and that of the surface-bound dyes. However, the net dye absorptance was increased by 4-5 times due to the strong interactions of the dye transition dipoles with the TAIF-scattered fields. The estimated SEF quantum yield in the low dye coverage limit suggests a markedly high radiative yield of the induced dipole in TAIF around approximately 0.5.     

Novel lasing action in dye-doped polymer films coated on large pseudotabular Ag islands

An approximately 15 microm thick polymer film doped (approximately 5 mM) with a laser dye, when coated on large pseudotabular Ag islands and pumped by a nanosecond laser, generated a single sharp stimulated emission with a bandwidth down to 2.5 nm. We attribute this novel, low-threshold (approximately 1 mJ/cm(2)) lasing action to the surface-enhanced fluorescence of the dyes very near the Ag islands. This highly surface-sensitive lasing concept was supported by the fact that the lasing action was almost completely eliminated by separating the Ag islands and the dye-doped polymer film with a molecularly thin (approximately 14 A) spacer.     

Stereoselective allylation of azirines with allylindium reagents

Allylindium reagents allylated azirines to give allylaziridines in good yields. The delivery of the allyl group was well regulated by the substituents at the C³-carbon of azirines. The cis-allylation with respect to the substituent was realized with azirines bearing a hydroxylmethyl or an acetoxymethyl group due to the chelation with allylindium reagents, whereas the trans-allylation was achieved with azirines substituted by a methyl, phenyl, or ester group owing to the steric repulsion.     

Allylgallation of cyclopropenes. Crystal structure of a novel cyclopropylgallium compound prepared by allylgallation of hydroxy-bearing cyclopropene

Allylgallation of cyclopropenes with allylgallium sesquibromide has been investigated; a novel cyclopropylgallium compound was isolated via allylgallation of hydroxy-bearing cyclopropene, and its structure was fully characterized by X-ray crystallography.     

GaCl3-catalyzed [4+2] annulations of allyltrimethylsilane and trimethyl(propargyl)silane with aldimines

The GaCl₃-catalyzed reaction of allyltrimethylsilane and aldimines gave tetrahydroquinolines in good yields. Similarly, 4-methylquinoline was obtained by using trimethyl(propargyl)silane via a dehydrogenation process.