With the optimal reaction conditions established, the scope of β-bromo amino acid esters (1) used in the 1,2-Nshift reactions was examined (Table ). An array of serinederivative feedstocks bearing symmetric benzyl groups on the N-atom, such as p-Cl/Me/t-Bu/FC6H4CH2, m-MeO/ClC6H4CH2, o-FC6H4CH2 and others, underwent cascade 1,2-N-shift/C-H coupling smoothly, affording the corresponding tetrahydroisoquinoline-4-carboxylates 2 (i.e., β-amino acid esters) in moderate to good yields (47%-75%, 2aa-2ah). In addition, β-bromo amino acid esters with more complex benzyl substituents, including disubstituted aromatic, alpha-naphthyl, and biphenyl groups, were accommodated under the optimal conditions for migratory C-H coupling (2al-2ai). Moreover, the configuration of product 2af was unambiguously confirmed by X-ray crystallography (see the SI for details). In addition, various alkyl substituents (R1) in the feedstock backbones, including npropyl, methyl, n-butyl, and iso-butyl, were well accommodated and led to the target cyclization products (2am-2ai) with excellent diastereoselectivity (dr >20:1). In addition, we investigated the C-H cyclization aptitude of different benzyl groups tethered to the N atom and observed that the more electron-rich aromatic groups preferentially cyclized to the radical intermediates (2au-2av). Next, by employing electron-effect or steric-effect of aromatic rings as the paired group on the N atom, the asymmetric C-H cyclization of β-bromo amino acid esters could be achieved, which afforded a variety of β-amino acid derivatives, possibly containing heterocyclic cores (2aw-2az). Given the practical interest in using sulfonates as the feedstock in the cascade 1,2-N-shift/C-H coupling, we next investigated the examples using the corresponding mesylate and tosylate instead of bromide. We found that serine-derived primary mesylate is a viable substrate in the presence of additive LiBr (2 equiv), albeit with slightly decreased yields. Such a strategy would provide an alternative approach to tetrahydroisoquinoline-4-carboxylates from readily available sulfonate feedstock, thereby avoiding the stepwise synthesis of the corresponding β-bromo amino acid esters. Furthermore, the five-membered rings could be constructed via a 1,2-Nshift by tuning the chain length of the aromatic ring tethered to the N atom on the feedstocks (2ba). However, our attempt to build six-membered rings via a 1,3-N shift migration using γ-bromo amino acid ester as feedstock failed, which revealed that the 1,3-N shift was not kinetically favored in this N-functionality migration process (2bb).