Unsymmetrical disulfides have been effectively prepared through thiol exchange with symmetrical disulfides employing a simple PdCl2/DMSO catalytic system. The given method features excellent functional group tolerance, a broad substrate scope, and operational simplicity. This reaction is especially useful for late-stage functionalization of bioactive scaffolds such as peptides and pharmaceuticals.
Disproportionation reaction of disulfides promoted by nitric oxide (NO) in the presence of oxygen
作者:Takashi Itoh、Nozomi Tsutsumi、Akio Ohsawa
DOI:10.1016/s0960-894x(99)00350-9
日期:1999.8
Two disulfides brought about disproportionationreaction to afford an unsymmetrical disulfide in 50% yield with a catalytic amount of nitricoxide in the presence of oxygen. The reaction proceeded faster when alkyl disulfides were employed for the reaction, and the substituent effects suggested that the reaction commenced with an oxidative process.
Cleavage of S-S Bond by Nitric Oxide (NO) in the Presence of Oxygen. A Disproportionation Reaction of Two Disulfides.
作者:Nozomi TSUTSUMI、Takashi ITOH、Akio OHSAWA
DOI:10.1248/cpb.48.1524
日期:——
experiments employing two symmetrical disulfides. The reaction resulted in the formation of unsymmetrical disulfides in nearly 50% yields. The steric hindrance of alkyl disulfide slowed the reactionrate, and an electron-donating group on the aryl disulfide promoted the reaction. The substituent and S-nitrosothiol effects suggested that the reaction was initialized with an oxidative process by NO+.
Na-exchanged X type zeolite, commercially available as MS-13X, effectively catalyzes thiol-disulfane exchange reactions under aerobic mild conditions to give the unsymmetrical disulfanes in good-to-high yields. Various thiols and disulfanes are tolerant in the catalytic systems. Preliminary mechanistic studies suggest the involvement of base-catalyzed SN2-S displacement and/or addition-elimination mechanisms
Na 交换的 X 型沸石,作为 MS-13X 可商购,在有氧温和条件下有效催化硫醇 - 二硫烷交换反应,以良好到高的产率得到不对称二硫烷。在催化系统中可以耐受各种硫醇和二硫烷。初步的机理研究表明,碱催化的 S N 2-S 置换和/或加成消除机制参与了氢键相互作用。