24 research outputs found
Benson group additivity values of phosphines and phosphine oxides : Fast and accurate computational thermochemistry of organophosphorus species
Composite quantum chemical methods W1X-1 and CBS-QB3 are used to calculate the gas phase
standard enthalpy of formation, entropy and heat capacity of 38 phosphines and phosphine oxides
for which reliable experimental thermochemical information is limited or simply nonexistent. For
alkyl phosphines and phosphine oxides, the W1X-1 and CBS-QB3 results are mutually consistent and
in excellent agreement with available G3X values and empirical data. In the case of aryl-substituted
species, different computational methods show more variation, with G3X enthalpies being furthest
from experimental values. The calculated thermochemical data are subsequently used to determine
Benson group additivity contributions for 24 Benson groups and group pairs involving phosphorus,
thereby allowing fast and accurate estimations of thermochemical data of many organophosphorus
compounds of any complexity. Such data are indispensable, for example, in chemical process design
or estimating potential hazards of new chemical compounds.peerReviewe
Discovery of Novel Tricyclic Heterocycles as Potent and Selective DPP‑4 Inhibitors for the Treatment of Type 2 Diabetes
In
our efforts to develop second generation DPP-4 inhibitors, we endeavored
to identify distinct structures with long-acting (once weekly) potential.
Taking advantage of X-ray cocrystal structures of sitagliptin and
other DPP-4 inhibitors, such as alogliptin and linagliptin bound to
DPP-4, and aided by molecular modeling, we designed several series
of heterocyclic compounds as initial targets. During their synthesis,
an unexpected chemical transformation provided a novel tricyclic scaffold
that was beyond our original design. Capitalizing on this serendipitous
discovery, we have elaborated this scaffold into a very potent and
selective DPP-4 inhibitor lead series, as highlighted by compound <b>17c</b>