Tunnel TLS similar to Websockets

Hi,

Is it possible to tunnel TLS on one host without terminating it like
Websockets are tunneled?
http://nginx.org/en/docs/http/websocket.html

location / {
proxy_pass http://backend;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection “upgrade”;
}

If I understand correctly, both Websockets and TLS send HTTP/1.1 CONNECT
request and than Upgrade header.

Can I use proxy_pass in a server block?

Thanks