Improved method for the conversion of pinacolboronic esters into trifluoroborate salts: facile synthesis of chiral secondary and tertiary trifluoroborates
作者:Viktor Bagutski、Abel Ros、Varinder K. Aggarwal
DOI:10.1016/j.tet.2009.10.002
日期:2009.11
A general method for the preparation of virtually any potassium trifluoroborate salt from the corresponding pinacolboronic ester is reported. Thus, conditions for an azeotropic removal of pinacol from the reaction mixture were found to afford the desired potassium trifluoroborates of sufficient purity (>95%) in nearly quantitative yields irrespective of the nature of the product. The utility of this
Development of Enantiospecific Coupling of Secondary and Tertiary Boronic Esters with Aromatic Compounds
作者:Marcin Odachowski、Amadeu Bonet、Stephanie Essafi、Philip Conti-Ramsden、Jeremy N. Harvey、Daniele Leonori、Varinder K. Aggarwal
DOI:10.1021/jacs.6b03963
日期:2016.8.3
functional groups (esters, azides, nitriles, alcohols, and ethers). The reaction also worked well with other electron-rich heteroaromatics and 6-membered ring aromatics provided they had donor groups in the meta position. Conditions were also found under which the B(pin)- moiety could be retained in the product, ortho to the boron substituent. This protocol, which created a new C(sp2)–C(sp3) and an adjacent
Visible‐Light‐Driven Strain‐Increase Ring Contraction Allows the Synthesis of Cyclobutyl Boronic Esters
作者:Raffael Davenport、Mattia Silvi、Adam Noble、Zied Hosni、Natalie Fey、Varinder K. Aggarwal
DOI:10.1002/anie.201915409
日期:2020.4.16
There are a limited number of ring-contraction methodologies which convert readily available five-membered rings into strained four-membered rings. Here we report a photo-induced radical-mediated ringcontraction of five-membered-ring alkenyl boronate complexes into cyclobutanes. The process involves the addition of an electrophilic radical to the electron-rich alkenyl boronate complex, leading to
The present invention relates to modulators of muscarinic receptors. The present invention also provides compositions comprising such modulators, and methods therewith for treating muscarinic receptor mediated diseases.
Enantiospecific, Regioselective Cross-Coupling Reactions of Secondary Allylic Boronic Esters
作者:Laetitia Chausset-Boissarie、Kazem Ghozati、Emily LaBine、Jack L.-Y. Chen、Varinder K. Aggarwal、Cathleen M. Crudden
DOI:10.1002/chem.201303683
日期:2013.12.23
enantioselective Suzuki–Miyaura cross‐coupling of chiral, enantioenriched secondaryallylic boronic esters is described (see scheme; DME=dimethoxyethane, Bpin = pinacolboryl, dba = dibenzylideneacetone). Mechanistic studies show that the reactions proceed via γ‐selective transmetalation followed by reductive elimination. The reaction provides the first independent confirmation that the transmetalation of