An efficient asymmetric Mannich/cyclizationcascade strategy was established from 2‐benzothiazolimines with N‐acylpyrazoles to provide optical active benzothiazolopyrimidine derivatives using a copper‐based complex. The mild cascade process constructed various structurally diverse products with broad scope of substrates together with excellent enantioselectivities (up to 99 % ee) and diastereoselectivities