5 research outputs found
A Dialkylsilylene-Pt(0) Complex with a DVTMS Ligand for the Catalytic Hydrosilylation of Functional Olefins
A platinum(0)
complex, bearing a 1,3-divinyl-1,1,3,3-tetraÂmethylÂdisiloxane
(DVTMS) and an isolable dialkylsilylene ligand, was successfully synthesized
by the reaction between the dialkylsilylene and Karstedt’s
catalyst. The downfield-shifted <sup>29</sup>Si NMR resonance, the
smaller <sup>1</sup><i>J</i><sub>Si,Pt</sub> value, and
the longer Si–Pt distance in this complex relative to the corresponding
parameters in related bisÂ(phosphine)-coordinated silylene-platinum
complexes suggest weaker π-back-donation from the Pt center
to the silylene, which is, however, still significant when compared
to related DVTMS-ligated Pt complexes bearing <i>N</i>-heterocyclic
carbenes, <i>N</i>-heterocyclic two-coordinate silylenes,
or base-stabilized three-coordinate silylenes. The title complex displays
excellent catalytic activity in the hydrosilylation of terminal olefins
that contain functional groups such as epoxide and amine moieties
Anthryl-Substituted 3‑Silylene-2-silaaziridine Obtained by Isomerization of Disilacyclopropanimine: An Exocyclic Silene Showing a Distinct Intramolecular Charge Transfer Transition
An anthryl-substituted exocyclic
silene, 3-silylene-2-silaaziridine,
was synthesized by isomerization of the corresponding disilacyclopropanimine.
The UV–vis spectrum of the silene shows a distinct intramolecular
charge transfer (ICT) transition from the π orbital of the SiC
double bond to the π* orbital of the anthryl moiety. The relatively
high-lying Ď€Â(Siî—»C) orbital of the 3-silylene-2-silaaziridine
moiety and the low-lying π* orbital of the anthryl group would
be responsible for the distinct ICT band
Anthryl-Substituted 3‑Silylene-2-silaaziridine Obtained by Isomerization of Disilacyclopropanimine: An Exocyclic Silene Showing a Distinct Intramolecular Charge Transfer Transition
An anthryl-substituted exocyclic
silene, 3-silylene-2-silaaziridine,
was synthesized by isomerization of the corresponding disilacyclopropanimine.
The UV–vis spectrum of the silene shows a distinct intramolecular
charge transfer (ICT) transition from the π orbital of the SiC
double bond to the π* orbital of the anthryl moiety. The relatively
high-lying Ď€Â(Siî—»C) orbital of the 3-silylene-2-silaaziridine
moiety and the low-lying π* orbital of the anthryl group would
be responsible for the distinct ICT band
Synthesis and Functionalization of a 1,4-Bis(trimethylsilyl)tetrasila-1,3-diene through the Selective Cleavage of Si(sp<sup>2</sup>)–Si(sp<sup>3</sup>) Bonds under Mild Reaction Conditions
Although the oxidative
coupling of disilenides, i.e., the disilicon
analogues of vinyl anions, represents a promising route to extend
the conjugation between Siî—»Si double bonds, previously reported
synthetic routes to disilenides involve strongly reducing conditions.
Herein, we report a novel synthetic route to disilenides from stable
disilenes via the selective cleavage of SiÂ(sp<sup>2</sup>)–SiÂ(sp<sup>3</sup>) bonds under milder reaction conditions. Using this method,
a 1,4-bisÂ(trimethylsilyl)Âtetrasila-1,3-diene (<b>5</b>) was
synthesized from the corresponding silyl-substituted disilene. Moreover,
Et<sub>3</sub>Si-substituted tetrasila-1,3-diene <b>7</b> was
synthesized via tetrasila-1,3-dien-1-ide <b>6</b>, which is
the first example of a functionalized tetrasila-1,3-diene
Hydrogen Bonds-Enabled Design of a <i>C</i><sub>1</sub>‑Symmetric Chiral Brønsted Acid Catalyst
We have developed new <i>C</i><sub>1</sub>-symmetric,
chiral bis-phosphoric acids with an electron-withdrawing group as
one of the two substituents. This <i>C</i><sub>1</sub>-symmetric,
chiral bis-phosphoric acid with a pentafluorophenyl group performs
exceptionally well in the asymmetric Diels–Alder reaction of
acrolein, methacrolein, and α-haloacroleins with substituted
amidodienes. Control over the atropisomeric catalyst structure, enhancement
of the catalytic activity, and differentiation of the asymmetric reaction
space is possible by the remote control of the pentafluorophenyl group.
Furthermore, we have conducted theoretical studies to clarify the
roles of both intra- and intermolecular hydrogen bonds in the <i>C</i><sub>1</sub>-symmetric chiral environment of chiral bis-phosphoric
acid catalysts. The developed strategy, <i>C</i><sub>1</sub>-symmetric catalyst design through hydrogen bonding, is potentially
applicable to the development of other chiral Brønsted acid catalysts