In vitro synthesis of pig kidney general acyl CoA dehydrogenase

In vitro synthesis of general acyl CoA dehydrogenase [EC 1.3.99.3], one of the mitochondrial flavoenzymes, was carried out to elucidate its biosynthetic mechanism. Poly(A)+ RNA isolated from pig kidney was translated in vitro using wheat germ lysate system and the synthesized enzyme was immunoprecipitated by the antibody against purified pig kidney general acyl CoA dehydrogenase. The apparent molecular weight of the synthesized protein was estimated to be approximately 1,000 daltons larger than that of the mature enzyme, indicating that general acyl CoA dehydrogenase in pig kidney is synthesized as a precursor with a larger molecular weight

A Highly Efficient Catalyst for the Synthesis of Alternating Copolymers with Thieno[3,4‑<i>c</i>]pyrrole-4,6-dione Units via Direct Arylation Polymerization

π-Conjugated polymers with a donor–acceptor (DA) combination of repeating units possess a narrow HOMO–LUMO gap, thus resulting in a high device performance in solar cells. This paper reports an improved catalytic system for the synthesis of DA polymers containing 5-(2-hexyldecyl)-5<i>H</i>-thieno­[3,4-<i>c</i>]­pyrrole-4,6-dione-1,3-diyl (TPD) group as the acceptor unit via palladium-catalyzed direct arylation polymerization. Although a related study has been reported (Angew. Chem. Int. Ed. 2012, 51, 2068), we attempted to reduce the catalyst loading because the palladium residue in π-conjugated polymers has been known to produce a detrimental effect on device performance. As a result, the amount of palladium could be reduced to 1/8 by using PdCl₂(MeCN)₂ and P­(C₆H₄-<i>o</i>-OMe)₃ (<b>L1</b>) as catalyst precursors. The polymerization smoothly proceeds at 100 °C in THF in the presence of pivalic acid and Cs₂CO₃ to afford TPD-based DA polymers <b>3a</b>–<b>3d</b> containing the following donor units in almost quantitative yields: 4,4′-dioctyl-2,2′-bithiophene-5,5′-diyl (<b>3a</b>, <i>M</i>_n = 36800, <i>M</i>_w/<i>M</i>_n = 2.20), 4,8-bis­(2-ethylhexyloxy)­benzo­[1,2-<i>b</i>:4,5-<i>b</i>′]­dithiophene-2,6-diyl (<b>3b</b>, <i>M</i>_n = 31100, <i>M</i>_w/<i>M</i>_n = 2.44), 3,4-(2,2′-dioctylpropylenedioxy)­thiophene-2,5-diyl (<b>3c</b>, <i>M</i>_n = 68200, <i>M</i>_w/<i>M</i>_n = 3.04), and 2,5-bis­(2-ethylhexyloxy)-1,4-phenylene (<b>3d</b>, <i>M</i>_n = 65500, <i>M</i>_w/<i>M</i>_n = 2.21). A detailed analysis of the structure of <b>3a</b> is reported

Disproportionation of Bis(phosphaethenyl)pyridine Iron(I) Bromide Induced by <i>t</i>BuNC

Redox behavior of Fe­(I) complexes bearing a PNP-pincer-type phosphaalkene ligand, 2,6-bis­[1-phenyl-2-(2,4,6-tri<i>-tert</i>-butylphenyl)-2-phosphaethenyl]­pyridine (BPEP-Ph), is reported. The four-coordinate Fe­(I) complex [FeBr­(BPEP-Ph)] (<b>1</b>) readily reacts with 1 equiv of <i>t</i>BuNC in toluene at −35 °C to give [FeBr­(<i>t</i>BuNC)­(BPEP-Ph)] (<b>2</b>) with a 17e configuration. Complex <b>2</b> is fairly stable in neat benzene at room temperature, but smoothly undergoes disproportionation in the presence of added <i>t</i>BuNC to afford the Fe(0) complex [Fe­(<i>t</i>BuNC)₂(BPEP-Ph)] (<b>3</b>) and the Fe­(II) complex [FeBr₂(<i>t</i>BuNC)₄] (<b>4</b>) along with free BPEP-Ph. The single-crystal X-ray diffraction studies of <b>3</b> and <b>4</b> reveal distorted trigonal bipyramidal and square pyramidal arrangements around Fe, respectively. The yield of <b>3</b> increases up to 50%/<b>2</b> when 2 equiv of <i>t</i>BuNC is added to the system. A disproportionation process involving a 19e intermediate is proposed

Disproportionation of Bis(phosphaethenyl)pyridine Iron(I) Bromide Induced by <i>t</i>BuNC

Redox behavior of Fe­(I) complexes bearing a PNP-pincer-type phosphaalkene ligand, 2,6-bis­[1-phenyl-2-(2,4,6-tri<i>-tert</i>-butylphenyl)-2-phosphaethenyl]­pyridine (BPEP-Ph), is reported. The four-coordinate Fe­(I) complex [FeBr­(BPEP-Ph)] (<b>1</b>) readily reacts with 1 equiv of <i>t</i>BuNC in toluene at −35 °C to give [FeBr­(<i>t</i>BuNC)­(BPEP-Ph)] (<b>2</b>) with a 17e configuration. Complex <b>2</b> is fairly stable in neat benzene at room temperature, but smoothly undergoes disproportionation in the presence of added <i>t</i>BuNC to afford the Fe(0) complex [Fe­(<i>t</i>BuNC)₂(BPEP-Ph)] (<b>3</b>) and the Fe­(II) complex [FeBr₂(<i>t</i>BuNC)₄] (<b>4</b>) along with free BPEP-Ph. The single-crystal X-ray diffraction studies of <b>3</b> and <b>4</b> reveal distorted trigonal bipyramidal and square pyramidal arrangements around Fe, respectively. The yield of <b>3</b> increases up to 50%/<b>2</b> when 2 equiv of <i>t</i>BuNC is added to the system. A disproportionation process involving a 19e intermediate is proposed