PERENCANAAN KEBUTUHAN MATERIAL (PKM) PADA PRODUKSI KINCIR ANGIN KAPASITAS 100 WATT

Banda Ace

Enantiospecific sp(2)-sp(3) coupling of secondary and tertiary boronic esters

The cross-coupling of boronic acids and related derivatives with sp² electrophiles (the Suzuki–Miyaura reaction) is one of the most powerful C–C bond formation reactions in synthesis, with applications that span pharmaceuticals, agrochemicals and high-tech materials. Despite the breadth of its utility, the scope of this Nobel prize-winning reaction is rather limited when applied to aliphatic boronic esters. Primary organoboron reagents work well, but secondary and tertiary boronic esters do not (apart from a few specific and isolated examples). Through an alternative strategy, which does not involve using transition metals, we have discovered that enantioenriched secondary and tertiary boronic esters can be coupled to electron-rich aromatics with essentially complete enantiospecificity. As the enantioenriched boronic esters are easily accessible, this reaction should find considerable application, particularly in the pharmaceutical industry where there is growing awareness of the importance of, and greater clinical success in, creating biomolecules with three-dimensional architectures

CCDC 909044: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures

CCDC 909045: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures

Reactivity of Lewis Acid Activated Diaza- and Dithiaboroles in Electrophilic Arene Borylation

Hydride abstraction from <i>N,N</i>′-bis­(adamantyl)-1-hydrido-1,3,2-benzodiazaborole with catalytic [Ph₃C]­[<i>closo</i>-CB₁₁H₆Br₆] resulted in a low yield of arene borylation and a major product derived from migration of both adamantyl groups to the arene backbone. In contrast, the related aryl-substituted diazaborole <i>N,N</i>′-(2,6-diisopropylphenyl)-1-bromo-1,3,2-diazaborole did not borylate benzene or toluene, being resistant to halide abstraction even with strong halide acceptors: e.g., [Et₃Si]­[<i>closo</i>-CB₁₁H₆Br₆]. The reactivity disparity arises from greater steric shielding of the boron p_<i>z</i> orbital in the 2,6-diisopropylphenyl-substituted diazaboroles. Boron electrophiles derived from 1-chloro-1,3,2-benzodithiaborole ((CatS₂)­BCl) are active for arene borylation, displaying reactivity between that of catecholato- and dichloro-boron electrophiles. [(CatS₂)­B­(NEt₃)]­[AlCl₄] is significantly less prone to nucleophile-induced transfer of halide from [AlCl₄]¯ to boron compared to catecholato<i> </i> and dichloro borocations, enabling it to borylate arenes containing nucleophilic −NMe₂ moieties in high conversion (e.g., <i>N,N</i>,4-trimethylaniline and 1,8-bis­(dimethylamino)­naphthalene). Calculations indicate that the magnitude of positive charge at boron is a key factor in determining the propensity of chloride transfer from [AlCl₄]¯ to boron on addition of a nucleophile

Reactivity of Lewis Acid Activated Diaza- and Dithiaboroles in Electrophilic Arene Borylation

Hydride abstraction from <i>N,N</i>′-bis­(adamantyl)-1-hydrido-1,3,2-benzodiazaborole with catalytic [Ph₃C]­[<i>closo</i>-CB₁₁H₆Br₆] resulted in a low yield of arene borylation and a major product derived from migration of both adamantyl groups to the arene backbone. In contrast, the related aryl-substituted diazaborole <i>N,N</i>′-(2,6-diisopropylphenyl)-1-bromo-1,3,2-diazaborole did not borylate benzene or toluene, being resistant to halide abstraction even with strong halide acceptors: e.g., [Et₃Si]­[<i>closo</i>-CB₁₁H₆Br₆]. The reactivity disparity arises from greater steric shielding of the boron p_<i>z</i> orbital in the 2,6-diisopropylphenyl-substituted diazaboroles. Boron electrophiles derived from 1-chloro-1,3,2-benzodithiaborole ((CatS₂)­BCl) are active for arene borylation, displaying reactivity between that of catecholato- and dichloro-boron electrophiles. [(CatS₂)­B­(NEt₃)]­[AlCl₄] is significantly less prone to nucleophile-induced transfer of halide from [AlCl₄]¯ to boron compared to catecholato<i> </i> and dichloro borocations, enabling it to borylate arenes containing nucleophilic −NMe₂ moieties in high conversion (e.g., <i>N,N</i>,4-trimethylaniline and 1,8-bis­(dimethylamino)­naphthalene). Calculations indicate that the magnitude of positive charge at boron is a key factor in determining the propensity of chloride transfer from [AlCl₄]¯ to boron on addition of a nucleophile