var desired = stringToReplace.replace(/[^\w\s]/gi, '')

As was mentioned in the comments it's easier to do this as a whitelist - replace the characters which aren't in your safelist.

The caret (^) character is the negation of the set [...], gi say global and case-insensitive (the latter is a bit redundant but I wanted to mention it) and the safelist in this example is digits, word characters, underscores (\w) and whitespace (\s).

Try with this function:

function removeSpecialChars(str) {
  return str.replace(/(?!\w|\s)./g, '')
    .replace(/\s+/g, ' ')
    .replace(/^(\s*)([\W\w]*)(\b\s*2');
}

• 1st regex /(?!\w|\s)./g remove any character that is not a word or whitespace. \w is equivalent to [A-Za-z0-9_]
• 2nd regex /\s+/g find any appearance of 1 or more whitespaces and replace it with one single white space
• 3rd regex /^(\s*)([\W\w]*)(\b\s*$)/g trim the string to remove any whitespace at the beginning or the end.

Use the global flag:

var name = name.replace(/[^a-zA-Z ]/g, "");
                                    ^

If you don't want to remove numbers, add it to the class:

var name = name.replace(/[^a-zA-Z0-9 ]/g, "");