  The interest in the physical properties of kagome lattices has risen
considerably. In addition to the synthesis of new materials, the possibility of
realizing ultracold atoms on an optical kagome lattice (KL) raises interesting
issues. For instance, by considering the Hubbard model on an anisotropic KL,
with a hopping $t^\prime$ along one of the directions, one is able to
interpolate between the Lieb lattice ($t^\prime=0$) and the isotropic KL
($t^\prime=t$). The ground state of the former is a ferrimagnetic insulator for
any on-site repulsion, $U$, while the latter displays a transition between a
paramagnetic metal and a Mott insulator. One may thus consider $t^\prime$ as a
parameter controlling the degree of magnetic frustration in the system. By
means of extensive quantum Monte Carlo simulations, we have examined magnetic
and transport properties as $t^\prime$ varies between these limits in order to
set up a phase diagram in the $(U/t, t^\prime/t)$ parameter space. As an
auxiliary response, analysis of the average sign of the fermionic determinant
provides consistent predictions for critical points in the phase diagram. We
observe a metal-insulator transition occurring at some critical point
$U_c^\text{M}(t^\prime)$, which increases monotonically with $ t^\prime $, from
the unfrustrated lattice limit. In addition, we have found that the boundary
between the ferrimagnetic insulator and the Mott insulator rises sharply with
$t^\prime$.
