2,6-Dichloro-9-thiabicyclo[3.3.1]nonane:  A Privileged, Bivalent Scaffold for the Display of Nucleophilic Components

Abstract

The title compound, the condensation product of sulfur dichloride and 1,5-cyclooctadiene, is a reliable acceptor of a wide variety of heteroatom nucleophiles, sometimes in reversible fashion. Optical resolution of the core structure has been achieved and preserved in succeeding transformations. The high reactivity and reliable stereochemical control afforded by this system illustrates the power of neighboring-group participation by the sulfur center.

The reaction of selenium dichloride with divinyl sulfide

“…It is known that a halogen atom is strongly activated in 2-haloethyl sulfides and selenides due to the anchimeric assistance effect with participation of sulfur or selenium atoms [25][26][27][28]. Nucleophilic substitution of halogen atoms in such compounds proceeds easily with a variety of nucleophiles.…”

Construction of Linear Polymers, Dendrimers, Networks, and Other Polymeric Architectures by Copper‐Catalyzed Azide‐Alkyne Cycloaddition “Click” Chemistry

“…[61] Structures with as many as 15 azobenzene moieties were prepared by iterative CuAAC/ S N 2 reactions (Scheme 15), taking advantage of the special anchimeric assistance reactivity of b-haloamine electrophiles with azide. [62] It was shown that, despite the steric hindrance within the dendrimer structure, all of the azobenzene groups could quantitatively be converted between cis and trans isomers reversibly using UV and visible light, respectively. The authors mention the potential of these dendrimers as fast, nanoscale, photoactive switches.…”

Addition of selenium dibromide to divinyl sulfide: spontaneous rearrangement of 2,6-dibromo-1,4-thiaselenane to 5-bromo-2-bromomethyl-1,3-thiaselenolane

“…The driving force for the rearrangement may be due to anchimeric assistance, [29][30][31] which causes high mobility of the bromine atom. This effect is important for the stabilization of cation 4, the assumed intermediate.…”

“…The halogen atom in 2-haloethyl sulfides and selenides is known to be strongly activated by the anchimeric assistance effect with participation of the sulfur or selenium atom. [29][30][31] Replacement of halogen atoms by a nucleophile in 2-haloethyl sulfides and selenides proceeds exceptionally easily. The formation of 3-membered thiirane and selenirane intermediates has been suggested to explain the considerable increase of the rate in nucleophilic substitution reactions.…”