Syntheses, structures, and complexation of cis‐ and trans‐cycloheptane‐1,2‐diyl‐fused crown thioethers ([12]ansS₄)

Abstract

cis‐ and trans‐Cycloheptane‐1,2‐diyl‐fused crown thioethers ([12]ansS4), 2,3‐cis‐ and 2,3‐trans‐cycloheptano‐1,4,7,10‐tetrathiacyclododecanes (cis‐2 and (±)‐trans‐2), were synthesized from newly prepared cis‐ and trans‐cycloheptane‐1,2‐ditiols, respectively. X‐ray diffraction analyses on cis‐2 and (–)‐trans‐2, which was obtained by optical resolution of (±)‐trans‐2 with a chiral column, showed that in cis‐2 the S‐C‐C‐S part fused with the cis‐cycloheptane‐1,2‐diyl adopted a gauche orientation and that in (–)‐trans‐2 all S‐C‐C‐S parts took anti‐conformations. A competitive complexation experiment of cis‐2 and (±)‐trans‐2 with AgOTf revealed that cis‐2 was more favorable than (±)‐trans‐2 for the complexation. The structure of [Ag(cis‐2)]NO3 was analyzed by X‐ray crystallography. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:388–396, 2011; View this article online at http://wileyonlinelibrary.com. DOI 10.1002/hc.20695

Convenient synthesis of 1,3-dithiolane-2-thiones: cyclic trithiocarbonates as conformational locks

“…This lock is powerful enough to make a methyl group axial, which requires 7.3 kJ/mol, 38 but fails to do the same with t-butyl (~20 kJ/mol 38 ). The lock can be subsequently removed or cleaved by reduction 4,13,26,27 or hydrolysis 27 of trithiocarbonates to dithiols. We suggest this approach as a potentially useful addition to a set of other conformational locks (acetals, ortho-esters, urethanes, etc.)…”

“…2,3 They are used as building blocks in the synthesis of new antibiotics, and as versatile ligands and polymers. [2][3][4][5][6] Trithiocarbonates are also of commercial importance in a wide variety of applications, for example as rubber stabilizers, ore flotation agents, and additives for lubricants and fuels. [7][8][9] Besides, they exhibit a remarkably high liver disorder suppressing effect, and hypocholesteremic, hypotriglyceridemic, radioprotective, and insecticidal activity.…”