Synthesis of a Hybrid <i>m</i>-Terphenyl/<i>o</i>-Carborane Building Block: Applications in Phosphine Ligand Design
作者:Christopher A. Lugo、Curtis E. Moore、Arnold L. Rheingold、Vincent Lavallo
DOI:10.1021/ic5030636
日期:2015.3.2
terphenyl/o-carborane ligand building block is synthesized by the reaction of m-terphenylalkyne with B10H14. This sterically demanding substituent can be installed into ligands, as demonstrated by the preparation of carboranylphosphine. The bulky phosphine reacts with [ClRh(CO)2]2 to produce monophosphine complex ClRhL(CO)2, which subsequently extrudes CO under vacuum to afford the dimeric species [ClRhL(CO)]2. The
Reduction of Dinitrogen to Ammonia at a Well-Protected Reaction Site in a Molybdenum Triamidoamine Complex
作者:Dmitry V. Yandulov、Richard R. Schrock
DOI:10.1021/ja020186x
日期:2002.6.1
ligand ([(RNCH2CH2)3N]3-) in which R is 3,5-(2,4,6-i-Pr3C6H2)2C6H3 (HexaIsoPropylTerphenyl or HIPT). The reaction between MoCl4(THF)2 and H3[HIPTN3N] in THF followed by 3.1 equiv of LiN(SiMe3)2 led to formation of orange [HIPTN3N]MoCl. Reduction of [HIPTN3N]MoCl with magnesium in THF under dinitrogen led to formation of salts that contain the [HIPTN3N]Mo(N2)}- ion. The [HIPTN3N]Mo(N2)}- ion can be oxidized
Site- and Enantioselective Formation of Allene-Bearing Tertiary or Quaternary Carbon Stereogenic Centers through NHC–Cu-Catalyzed Allylic Substitution
作者:Byunghyuck Jung、Amir H. Hoveyda
DOI:10.1021/ja211269w
日期:2012.1.25
Catalyticenantioselective allylic substitutions that result in addition of an allenyl group (<2% propargyl addition) and formation of tertiary or quaternary C-C bonds are described. Commercially available allenylboronic acid pinacol ester is used. Reactions are promoted by a 5.0-10 mol % loading of sulfonate-bearing chiral bidentate N-heterocyclic carbene (NHC) complexes of copper, which exhibit the
Copper–Hydride-Catalyzed Enantioselective Processes with Allenyl Boronates. Mechanistic Nuances, Scope, and Utility in Target-Oriented Synthesis
作者:Yu Sun、Yuebiao Zhou、Ying Shi、Juan del Pozo、Sebastian Torker、Amir H. Hoveyda
DOI:10.1021/jacs.9b05465
日期:2019.7.31
opposed to the commonly utilized boron-copper exchange. The utility of the approach is demonstrated by applications to concise preparation of the linear fragment of pumiliotoxin B (myotonic, cardiotonic) and enantioselective synthesis and structure confirmation of netamine C, a member of a family of anti-tumor and anti-malarial natural products. Completion of the latter routes required the following
Generation of Axially Chiral Fluoroallenes through a Copper-Catalyzed Enantioselective β-Fluoride Elimination
作者:Thomas J. O’Connor、Binh Khanh Mai、Jordan Nafie、Peng Liu、F. Dean Toste
DOI:10.1021/jacs.1c05769
日期:2021.9.1
difluorides to generate axiallychiral, tetrasubstituted monofluoroallenes in both good yields (27 examples >80%) and enantioselectivities (82–98% ee). Compared to previously reported synthetic routes to axiallychiralallenes (ACAs) from prochiral substrates, a mechanistically distinct reaction has been developed: the enantiodiscrimination between enantiotopic fluorides to set an axial stereocenter. DFT