Your resulting regexp, and the code you use to create it, is simpler if you factor out the common \s. 
my $string = join '|', map {quotemeta} @phrases;
$sentence =~ s/(\s$string\s)/#$1#/g;

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But I guess your biggest problem is that the regexp uses $phrases, while the join creates $string.

In reply to Re: map function use by JavaFan
in thread map function use by newbio

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