Synthetic approaches towards the synthesis of beta-blockers (betaxolol, metoprolol, sotalol, and timolol)

Numerous efficient synthetic methodologies have been elaborated for the synthesis of $\beta $-blockers since the introduction of propranolol (a beta-blocker) in 1968. In this review, focus is placed on the more concise asymmetric and bioenzymatic synthetic approaches attempted towards the synthesis of beta-blockers (betaxolol, metoprolol, sotalol, and timolol).