Acid test for Tyr and Trp : S -Acetamidomethyl cysteine sulfoxide (Cys(Acm)(O)) enables the residue-selective C−H sulfenylation of Tyr or Trp under appropriately selected acidic reaction conditions. 源自 Cys(Acm)(O) 的双阳离子中间体选择性地与 Tyr 反应,而S-氯半胱氨酸允许 Trp 选择性硫化。实现了肽的装订和脂化的一锅序列。