JSFiddle - React, Tailwind, and code Playground

HTML

<input onkeyup="corrigirValor(this)" required class="inp_editar" type="text" name="nome_cont" id="input-1" />

JavaScript

var ignorar = ["das", "dos", "e", "é", "do", "da", "de"];

function caixaAlta(string) {
    return String(string).toLowerCase().replace(/([^A-zÀ-ú]?)([A-zÀ-ú]+)/g, function(match, separator, word) {
        if (ignorar.indexOf(word) != -1) return separator + word;
        return separator + word.charAt(0).toUpperCase() + word.slice(1);
    });
}

function corrigirValor(el) {
    el.value = caixaAlta(el.value);
}