iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu

iptables -t nat -A PREROUTING -p tcp --dport 1111 -j DNAT --to-destination 2.2.2.2:1111
iptables -t nat -A POSTROUTING -d 2.2.2.2 -p tcp --dport 1111 -j MASQUERADE

Reference: https://superuser.com/questions/1011613/iptables-masquerade-only-selected-ports