How to send user created articles to approval queue?
I'm not sure this is what you need but maybe you can achieve this using Rules. I've created a rule for nodes of type 'forum topic' and this is an example:


Event: Before saving content of type your type
Conditions: Data comparison -- Parameter: Data to compare: [node:is-new], Data value: true
Actions:

Conditional

If: User has role(s): Parameter: User: [node:author], Roles: new, Match roles: any

Set a data value: Parameter: Data: [node:status], Value: Unpublished
Show a message on the site: Parameter: Message: your message, Message type: Warning, Repeat message: false







The exported rule:

{ "rules_forum_needs_approval" : {
    "LABEL" : "Forum needs approval",
    "PLUGIN" : "reaction rule",
    "OWNER" : "rules",
    "REQUIRES" : [ "rules", "rules_conditional", "rules_i18n" ],
    "ON" : { "node_presave--forum" : { "bundle" : "forum" } },
    "IF" : [ { "data_is" : { "data" : [ "node:is-new" ], "value" : 1 } } ],
    "DO" : [
      { "CONDITIONAL" : [
          {
            "IF" : { "user_has_role" : {
                "account" : [ "node:author" ],
                "roles" : { "value" : { "14" : "14" } },
                "operation" : "OR"
              }
            },
            "DO" : [
              { "data_set" : { "data" : [ "node:status" ], "value" : "0" } },
              { "drupal_message" : {
                  "message" : "[node:title] needs approval.",
                  "type" : "warning",
                  "repeat" : 0
                }
              }
            ]
          }
        ]
      }
    ]
  }
}