3 research outputs found
Regioselective Gold-Catalyzed Oxidative C–N Bond Formation
A novel protocol
for the regioselective intermolecular amination
of various arenes has been developed. By using an IÂ(III) oxidant in
the presence of a AuÂ(I) catalyst, a direct and novel route for regioselectively
accessing a variety of substituted aniline moieties has been achieved
with yields as high as 90%. Mechanistic insight suggests that regioselectivity
can be predicted based on electrophilic aromatic metalation patterns
Oxidative Cross-Coupling of sp<sup>3</sup>- and sp<sup>2</sup>‑Hybridized C–H Bonds: Vanadium-Catalyzed Aminomethylation of Imidazo[1,2‑<i>a</i>]pyridines
The
vanadium-catalyzed oxidative coupling of substituted 2-arylimidiazoÂ[1,2-<i>a</i>]Âpyridines to <i>N</i>-methylmorpholine oxide,
which acts as both a coupling partner and an oxidant, has been achieved.
This reaction was applied to various substituted imidiazoÂ[1,2-<i>a</i>]Âpyridine and indole substrates, resulting in yields as
high as 90%. Mechanistic investigations indicate that the reaction
may proceed via a Mannich-type process. This work demonstrates how
oxidative aminomethylation can be used as a useful method to introduce
tertiary amines into heterocycles, thus providing an alternative method
for conventional Mannich-type reactions
Cyclodextrin-Based Pseudorotaxanes: Easily Conjugatable Scaffolds for Synthesizing Hyperpolarized Xenon-129 Magnetic Resonance Imaging Agents
Hyperpolarized (HP)
xenon-129 (Xe) magnetic resonance (MR) imaging
has the potential to detect biological analytes with high sensitivity
and high resolution when coupled with xenon-encapsulating molecular
probes. Despite the development of numerous HP Xe probes, one of the
challenges that has hampered the translation of these agents from
in vitro demonstration to in vivo testing is the difficulty in synthesizing
the Xe-encapsulating cage molecule. In this study, we demonstrate
that a pseudorotaxane, based on a Îł-cyclodextrin macrocycle,
is easily synthesized in one step and is detectable using HyperCEST-enhanced <sup>129</sup>Xe MR spectroscopy