documentclass{book}

usepackage{blindtext}
usepackage{xparse}


makeatletter

letlatex@chapterchapter

defcurrentchaptername{}

NewDocumentCommand{notocchapter}{om}{%
  IfValueTF{#1}{%
    defcurrentchaptername{#1}
  }{%
    defcurrentchaptername{#2}
  }%
  begingroup
  renewcommand{addcontentsline}[3]{}% Do nothing for this chapter
  IfValueTF{#1}{%
    latex@chapter[#1]{#2}
  }{%
    latex@chapter{#2}
  }%
  endgroup
}

NewDocumentCommand{lookslikeachapterentrybutpointstosomewhereelse}{o}{%
  phantomsection
  IfValueTF{#1}{%
    addcontentsline{toc}{chapter}{protectnumberline{thechapter}#1}%
  }{%
    addcontentsline{toc}{chapter}{protectnumberline{thechapter}currentchaptername}
  }%
}

makeatother

usepackage[linktocpage]{hyperref}


begin{document}

tableofcontents

notocchapter{Some chapter}

blindtext[20]

lookslikeachapterentrybutpointstosomewhereelse

chapter{Some other chapter}

notocchapter{Another chapter}

blindtext[40]

lookslikeachapterentrybutpointstosomewhereelse[And now for something completely different]


end{document}