Perubahan Struktural Dalam Pembangunan Perkotaan

Pertumbuhan daerah kota di negra berkembang menunjukan gejala yang tidak di harapkan.untuk mengantisipasi kondisi keterbelakangan ini, daerah perkotaan haurus di dorong secara kuat untuk meningkatkan permintaan terhadap barang dan pelayanan untuk seluruh kepentingan nasional. permasalahan kota yang telah di hadapi bukan hanya persoalan keruangan dan Perubahan struktur ekonomi saja, tapi juga pembentukan implikasi sosial dan lingkungan. hal ini dapat di lihat di Bogota dengan pola dualisme sistem sosialnya, adanya pemisahan ruang antara masyarakat kaya di daerah utara dan masyarakat miskin di daerah selatan dan barat. Fenomena serupa juga di temukan di Indonesia. Jakarta yang berkembang secara cepat dengan dukungan sektor manufaktur dan keuanga, mencapai kondisi ekonomi dan pendapatan yang baik. Bagaimanapun, di Balik kondisi tersebut, ditemukan biaya yang tak terhindarkan secara nyata, yang umum muncul berupa penurunan kualitas lingkungan. Beberapa kebijaksanaan direkomendasikan adalah: (1) Meningkatkan produktivitas ekonomi wilayah kota yang terintegrasi ke dalam pembangunan regional dan pedesaan, (2) Meningkatkan produktivitas kelompok miskin perkotaan melalui perbaikan infrastruktur sosial dan perluasan kesempatan kerja, (3) Menghindari Perusakan lingkungan serta konsekwensi lainnya di sekitar wilayah masyarakat miskin, dan (4) Membangun persepsi yang seimbang terhadap pembangunan kota dan permasalahan-permasalahan yang berkaitan dengannya: pemerintah, sektor swasta, dan masyarakat

Examination of Acid-Fast Bacilli in Sputum Using Modified Light Microscope with Homemade Light Emitting Diode Additional Attachment

Typical clinical symptoms and chest X-ray is a marker of Tuberculosis (TB) sufferers. However, the diagnosis of TB in adults should be supported by microscopic examination. Currently, Bacilli microscopic examination of acid-fast bacilli (AFB) in sputum by Ziehl-Neelsen (ZN) coloring is the most widely used. However, for reasons of convenience, especially for laboratories with a considerable amount of smear samples, and due to higher sensitivity compared with ZN staining, the World Health Organization (WHO) has recommended the use of auramine-O-staining (fluorochrome  staining), which is visualized by light emitting diode (LED) fluorescence microscopy. The aim of this study was to evaluate the performance of modified light microscope with homemade LED additional attachment for examination of AFB in sputum using auramine-O-staining method. We compared the sensitivity and specificity of 2 kinds of AFB in sputum methods: ZN and fluorochrome, using culture on Lowenstein-Jensen media as the gold standard. The results showed auramine-O-staining gives more proportion of positive findings (81%) compared to the ZN method (70%). These results demonstrated that the sensitivity of auramine-O-staining was higher than ZN, however it gives more potential false positive results than ZN. The sensitivity of auramine-O-staining in detecting AFB in sputum was 100% while the specificity was 88%

Synthesis and Reactivity of Magnesium Complexes Supported by Tris(2-dimethylaminoethyl)amine (Me₆tren)

The reaction of tris­(2-dimethylaminoethyl)­amine (Me₆tren) with Grignard reagents and related Mg precursors has been investigated. Treating Me₆tren with 2 equiv of PhMgBr in diethyl ether resulted in the formation of [(Me₆tren)­MgBr]Br (<b>1</b>), in which Me₆tren is bound in a κ⁴ fashion. This is the first example of a Mg complex containing Me₆tren or a related tris­(aminoethyl)­amine ligand. In contrast, when MeMgBr was treated with either 1 or 2 equiv of Me₆tren, a mixture containing <b>1</b> and the alkyl species [(Me₆tren)­MgMe]Br (<b>3</b>) was produced. It was not possible to separate the two compounds to generate a pure sample of <b>3</b>. Reaction between Me₆tren and greater than 4 equiv of MeMgBr formed [(Me₆tren)­MgBr]₂[MgBr₄] (<b>4</b>), an analogue of <b>1</b> with a different counterion. The highly unusual dialkyl Mg compound (Me₆tren)­MgMe₂ (<b>5</b>), which features a κ³-bound Me₆tren ligand, was synthesized through the reaction of Me₂Mg with Me₆tren. The reaction of <b>5</b> with excess phenylacetylene or carbon dioxide yielded (Me₆tren)­Mg­(CCPh)₂ (<b>6</b>) and Mg­(OAc)₂, respectively, while treatment with benzylalcohol, benzylamine, 4-<i>tert</i>-butylcatechol, 4-<i>tert</i>-butylphenol, and aniline all resulted in decomposition. The addition of 1 equiv of 2,6-lutidine·HBAr^F (BAr^F = tetrakis­(3,5-bis­(trifluoromethyl)­phenyl)­borate) to <b>5</b> formed [(Me₆tren)­MgMe]­BAr^F (<b>7</b>), a rare example of a neutral ancillary ligand supported cationic monoalkyl Mg species. Compounds <b>1</b>, <b>4</b>, and <b>5</b> have been crystallographically characterized

Synthesis and Reactivity of Magnesium Complexes Supported by Tris(2-dimethylaminoethyl)amine (Me₆tren)

The reaction of tris­(2-dimethylaminoethyl)­amine (Me₆tren) with Grignard reagents and related Mg precursors has been investigated. Treating Me₆tren with 2 equiv of PhMgBr in diethyl ether resulted in the formation of [(Me₆tren)­MgBr]Br (<b>1</b>), in which Me₆tren is bound in a κ⁴ fashion. This is the first example of a Mg complex containing Me₆tren or a related tris­(aminoethyl)­amine ligand. In contrast, when MeMgBr was treated with either 1 or 2 equiv of Me₆tren, a mixture containing <b>1</b> and the alkyl species [(Me₆tren)­MgMe]Br (<b>3</b>) was produced. It was not possible to separate the two compounds to generate a pure sample of <b>3</b>. Reaction between Me₆tren and greater than 4 equiv of MeMgBr formed [(Me₆tren)­MgBr]₂[MgBr₄] (<b>4</b>), an analogue of <b>1</b> with a different counterion. The highly unusual dialkyl Mg compound (Me₆tren)­MgMe₂ (<b>5</b>), which features a κ³-bound Me₆tren ligand, was synthesized through the reaction of Me₂Mg with Me₆tren. The reaction of <b>5</b> with excess phenylacetylene or carbon dioxide yielded (Me₆tren)­Mg­(CCPh)₂ (<b>6</b>) and Mg­(OAc)₂, respectively, while treatment with benzylalcohol, benzylamine, 4-<i>tert</i>-butylcatechol, 4-<i>tert</i>-butylphenol, and aniline all resulted in decomposition. The addition of 1 equiv of 2,6-lutidine·HBAr^F (BAr^F = tetrakis­(3,5-bis­(trifluoromethyl)­phenyl)­borate) to <b>5</b> formed [(Me₆tren)­MgMe]­BAr^F (<b>7</b>), a rare example of a neutral ancillary ligand supported cationic monoalkyl Mg species. Compounds <b>1</b>, <b>4</b>, and <b>5</b> have been crystallographically characterized

Selective Iron-Catalyzed <i>N</i>‑Formylation of Amines using Dihydrogen and Carbon Dioxide

A family of iron­(II) carbonyl hydride species supported by PNP pincer ligands was identified as highly productive catalysts for the <i>N-</i>formylation of amines via CO₂ hydrogenation. Specifically, iron complexes supported by two different types of PNP ligands were examined for formamide production. Complexes containing a PNP ligand with a tertiary amine afforded superior turnover numbers in comparison to complexes containing a bifunctional PNP ligand with a secondary amine, indicating that bifunctional motifs are not required for catalysis. Systems incorporating a tertiary amine containing a PNP ligand were active for the <i>N-</i>formylation of a variety of amine substrates, achieving TONs up to 8900 and conversions as high as 92%. Mechanistic experiments suggest that <i>N-</i>formylation occurs via an initial, reversible reduction of CO₂ to ammonium formate followed by dehydration to produce formamide. Several intermediates relevant to this reaction pathway, as well as iron-containing deactivation species, were isolated and characterized

Nitrogen Fixation Revisited on Iron(0) Dinitrogen Phosphine Complexes

A reinvestigation of the treatment of [Fe­(N₂)­(PP)₂] (PP = depe, dmpe) with acid revealed no ammonium formation. Instead, rapid protonation at the metal center to give hydride complexes was observed. Treatment of [Fe­(N₂)­(dmpe)₂] with methylating agents such as methyl triflate or methyl tosylate resulted in methylation of the metal center to afford [FeMe­(N₂)­(dmpe)₂]⁺. Treatment of [Fe­(N₂)­(dmpe)₂] with trimethylsilyl triflate, however, resulted in reaction at dinitrogen affording NH₄⁺ on subsequent treatment with acid. The side-on bound hydrazine complex [Fe­(N₂H₄)­(dmpe)₂]²⁺ and bis­(ammonia) complex [Fe­(NH₃)₂­(dmpe)₂]²⁺ were identified by ¹⁵N NMR spectroscopy as other species formed in the reaction mixture

Selective Iron-Catalyzed Deaminative Hydrogenation of Amides

The five-coordinate iron­(II) hydride complex (^<i>i</i>PrPNP)­Fe­(H)­CO (^<i>i</i>PrPNP = N­[CH₂CH₂(P^<i>i</i>Pr₂)]₂) was found to selectively catalyze deaminative hydrogenation of amides to the corresponding amines and primary alcohols. It is one of the most active amide hydrogenation catalysts reported to date, with turnover numbers (TONs) in excess of 1000 observed for multiple substrates and TONs greater than 4000 obtained for activated formanilides. The amide C–N cleavage reactions occur with a preference for electron-withdrawing substituents and with greater activity for formamides compared with acetamides and benzamides. Stoichiometric reactions between (^<i>i</i>PrPNP)­Fe­(H)­CO and formanilide afforded the new iron­(II) complex (^<i>i</i>PrPN^HP)­Fe­(H)­CO­(N­(Ph)­HCO) resulting from N–H addition across the Fe–N bond. Complexes of this type were identified as the resting state during catalytic hydrogenation reactions containing secondary amides. Addition of a Lewis acid cocatalyst provided further enhancement of the productivity of catalytic amide hydrogenations

Understanding Precatalyst Activation in Cross-Coupling Reactions: Alcohol Facilitated Reduction from Pd(II) to Pd(0) in Precatalysts of the Type (η³‑allyl)Pd(L)(Cl) and (η³‑indenyl)Pd(L)(Cl)

Complexes of the type (η³-allyl)­Pd­(L)­(Cl) (L = PR₃ or NHC), have been used extensively as precatalysts for cross-coupling and related reactions, with systems containing substituents in the 1-position of the η³-allyl ligand, such as (η³-cinnamyl)­Pd­(L)­(Cl), giving the highest activity. Recently, we reported a new precatalyst scaffold based on an η³-indenyl ligand, (η³-indenyl)­Pd­(L)­(Cl), which typically provides higher activity than even η³-cinnamyl supported systems. In particular, precatalysts of the type (η³-1-^tBu-indenyl)­Pd­(L)­(Cl) give the highest activity. In cross-coupling reactions using this type of Pd­(II) precatalyst, it is proposed that the active species is monoligated Pd(0), and the rate of reduction to Pd(0) is crucial. Here, we describe detailed experimental and computational studies which explore the pathway by which the Pd­(II) complexes (η³-allyl)­Pd­(IPr)­(Cl) (IPr = 1,3-bis­(2,6-diisopropylphenyl)-1,3-dihydro-2H-imidazol-2-ylidene), (η³-cinnamyl)­Pd­(IPr)­(Cl), (η³-indenyl)­Pd­(IPr)­(Cl) and (η³-1-^tBu-indenyl)­Pd­(IPr)­(Cl) are reduced to Pd(0) in alcoholic solvents, which are commonly used in Suzuki–Miyaura and α-arylation reactions. The rates of reduction for the different precatalysts are compared and we observe significant variability based on the exact reaction conditions. However, in general, η³-indenyl systems are reduced faster than η³-allyl systems, and DFT calculations show that this is in part due to the ability of the indenyl ligand to undergo facile ring slippage. Our results are consistent with the η³-indenyl systems giving increased catalytic activity and provide fundamental information about how to design systems that will rapidly generate monoligated Pd(0) in the presence of alcohols

Stoichiometric and Catalytic Reactions of Thermally Stable Nickel(0) NHC Complexes

Although there are many organic reactions that are catalyzed by either Ni⁰ or Pd⁰ complexes, in comparison with the case for Pd⁰ there has been significantly less work studying coordinatively unsaturated Ni⁰ complexes. Here, we develop a simple synthetic route for preparing a number of thermally stable NHC-supported Ni⁰ hexadiene complexes in good yield. We examine the stoichiometric reactivity of one of these species and demonstrate that the coordinated hexadiene moiety is labile and can be replaced with a variety of different ligands, including CO, phosphines, isonitriles, and olefins. In addition, we show that the Ni⁰ hexadiene complexes are relatively rare examples of homogeneous first-row transition-metal catalysts for the hydrogenation of olefins

Iron-Catalyzed Amide Formation from the Dehydrogenative Coupling of Alcohols and Secondary Amines

The five-coordinate iron­(II) hydride complex (^<i>i</i>PrPNP)­Fe­(H)­(CO) (^<i>i</i>PrPNP = N­[CH₂CH₂(P^<i>i</i>Pr₂)]₂) selectively catalyzes the dehydrogenative intermolecular coupling of alcohols and secondary amines to form tertiary amides. This is the most productive base-metal catalyst for dehydrogenative amidation reported to date, in some cases achieving up to 600 turnovers. The catalyst works well for sterically undemanding amines and alcohols or cyclic substrates and is particularly effective in the synthesis of formamides from methanol. However, the catalyst performance declines rapidly with the incorporation of large substituents on the amine or alcohol substrate. Variable-temperature NMR spectroscopic studies suggest that the catalyst resting state is an off-cycle iron­(II) methoxide species, (^<i>i</i>PrPN­(H)­P)­Fe­(H)­(OCH₃)­(CO), resulting from addition of methanol across the Fe–N bond of (^<i>i</i>PrPNP)­Fe­(H)­(CO). This reversibly formed iron­(II) methoxide complex is favored at mild temperatures but eliminates methanol upon heating