documentclass{book}
usepackage[utf8]{inputenc}
usepackage{tocloft}
usepackage{hyperref}

begin{document}

tableofcontents

%======== USING REGULAR ENTRIES ========
chapter{Chapter 1} % properly linked of course
{LARGE This is chapter 1}

section{Section 1-1} % well linked as well
{LARGE This is chapter 1 section 1}
clearpage

%======== USING addcontentsline ========
phantomsection
addcontentsline{toc}{chapter}{Chapter 2} % works fine
{LARGE This is chapter 2}
clearpage

phantomsection
addcontentsline{toc}{section}{Section 2-1} % link works
{LARGE This is chapter 2 section 1}
clearpage

%======== USING addtocontents ========
phantomsection
addtocontents{toc}{protectcontentsline{chapter} % this link does not work
{protectnumberline{3}Chapter 3}{thepage}{}}
{LARGE This is chapter 3}
clearpage

phantomsection
addtocontents{toc}{protectcontentsline{section}{protectnumberline{3-1}Section 3-1}{thepage}{section*.2.4}} % ... neither does this
{LARGE This is chapter 3 section 1}
clearpage

end{document}

chapter*.thechapter
chapter*.thepage
section*.thesection