One-pot reductive amination and Suzuki-Miyaura cross-coupling of formyl aryl and heteroaryl MIDA boronates in array format

Formyl-substituted aryl and heteroaryl MIDA boronates were prepared by a DMSO-free method and used in the first reported one-pot reductive amination-Suzuki-Miyaura cross-coupling sequence. This sequence was then carried out in parallel array format, using microwave-assisted in situ release cross-coupling of MIDA boronates to generate a library with diversity along two axes, affording rapid and convenient access to an array of druglike molecules.     

Regioselective synthesis and slow-release Suzuki-Miyaura cross-coupling of MIDA boronate-functionalized isoxazoles and triazoles

The efficient preparation of heterocycles with a range of substitutions ortho to heteroatoms remains as a challenge in organic synthesis, particularly relevant to the construction of druglike molecules due to the ubiquitous presence of such moieties in that chemical space. Modular installation of heterocyclic building blocks using Suzuki-Miyaura cross-coupling is a conceptually useful strategy to address this challenge, though this has historically been met with technical difficulty due to issues of inaccessibility and instability of the requisite heterocyclic boronates. Herein we report a mild and highly regioselective cycloaddition approach which affords convenient access to stable MIDA boronate-functionalized isoxazoles and triazoles and their subsequent efficient Suzuki-Miyaura cross-coupling. This methodology is then further applied to a set of druglike compounds in an efficient one-pot telescoped sequence in line with green chemistry principles.     

Formation and signature of quark matter in relativistic ion collisions

Exclusively using experimental information on particle production in nucleon-nucleon interactions, this paper attempts to demonstrate that: (i) the characteristics of relativistic collisions between heavy nuclei are determined by quark physics, not conventional nuclear physics; (ii) the formation of quark matter in such collisions can be observed experimentally via large multiplicities, copious production of photons (not from π decay), the anomalous strangeness, charm and baryon number structure of the events, and appearance of structure in the rapidity distribution; (iii) the formation of quark matter has actually been observed in high energy cosmic ray interactions. We show that the 100 TeV threshold for the appearance of anomalous interactions reflects the transition from nucleonic to quark structure of the nucleus. Observed anomalies match the signatures of quark matter formation in (ii); (iv) our results imply the abundant presence of heavy nuclei, e.g. Fe, in the high energy cosmic ray spectrum. Cosmic ray interactions above 100 TeV can eventually be used to study the vacuum structure of quantum chromodynamics and the disappearance of spontaneous symmetry breaking due to the restoration of symmetry at high matter densities.