Methoxycarbonylsulfenyl chloride

V-BOC thiazolidines can be cleaved with ScmCl (methoxycarbonylsulfenyl chloride) (AcOH, DMF, H2O) to afford the Sem derivative in >90% yield. ... 

Methoxycarbonylsulfenyl chloride (SMoc-Q)P is a valuable reagent for the synthesis of asynunetric disulfides via reasonably stable, isolable 5-(methoxycarbonylsulfanyl) derivatives. This procedure has been successfully transferred to cysteine peptides for selective intrachain and interchain disulfide formation (see Vol.E22b, Section 6.1.3.1). Due to the high reactivity of 5-(methoxycarbonylsulfanyl)cysteine derivatives 9 (Scheme 21), and complications arising from their base lability and the risk of S N nnigration, this type of protection is not suitable for multistep peptide synthesis. The more recently proposed AT-methyl-AT-phenylcarbamoylsulfanyl (SMpc) derivative of cysteine (Scheme 21) is apparently less prone to sulfur to nitrogen shift. ... 

This special sulfhydryl protecting group can be introduced via the reaction of an S-trityl derivative with methoxycarbonylsulfenyl chloride... 

Altemate Names methoxycarbonylsulfenyl chloride, 5-chloro-O-methylthiocarbonate. 

Introduction. Methoxycarbonylsulfenyl chloride (Scm-Cl), easily prepared from equimolar amounts of methanol and chlorocarbonylsulfenyl chloride (eq 1), finds many applications, based on the reactivity of alkoxycarbonylsulfenyl chlorides against thiols. Brois and co-workers realized the value of methoxycarbonylsulfenyl chloride in the synthesis of asymmetric disulfides, which led to important applications in the chemistry of cysteine and its derivatives, particularly cysteinyl peptides. Other applications include preparation of aromatic thiols, symmetric trisulfides, etc. The applicability of Scm-Cl surpasses its drawbacks which include relatively short storage life (1-2 months at —20°C in sealed ampules) and relatively rapid hydrolysis in the protic media that some of its most important uses require. 

Formation of Unsymmetrical Disulfides. This facile protocol (eq O proceeds through sulfenyl thiocarbonate intermediates obtained in very good yields from equimolar amounts of thiols and alkoxycarbonylsulfenyl chlorides (of which methoxycarbonylsulfenyl chloride is widely used) at low temperature (generally 0-10 °C), in solvents such as methanol, chloroform, dichloromethane, and dioxane. An oxygen-free atmosphere of nitrogen is recommended. ... 

Cyclization of Hydroxamates i-Cysteine-derived thiazolidine hydroxamate ester 71 is cyclized to the thiazolidine-fused fS-lactams 72 using methyl sulfonyl chloride [63]. The cleavage of the thiazolidine ring with methoxycarbonylsulfenyl chloride afforded the monocyclic fS-lactam 74 (Scheme 3.28). An Sml2-mediated scission of the N-O bond in 72 followed by cleavage of the thiazolidine ring afforded the NH monocyclic -lactam 73 in reasonable yield (Scheme 3.28). 

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