@echo off

rem if unicode in path
rem chcp 65001

set folder=%userprofile%\desktop\test
set pattern=%folder%\*.jpg

setlocal EnableDelayedExpansion
for /f "delims=" %%a in ('dir /b "%pattern%"') do (
  set filename=%%a
  set x1=!filename: =/!
  set x2=!x1:]= !
  for %%b in (!x2!) do (
    set last=%%b
  )
  set new_filename=!last:/= !
  set src=!folder!\!filename!
  set dst=!folder!\!new_filename!
  echo do move "!src!" to "!dst!"

  move "!src!" "!dst!"
)