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oai:figshare.com:article/34068797 2026-10-05T09:04:59Z category_1 category_4 category_7 category_12 category_15 category_24 category_873 category_132 portal_63 item_type_3 month_year_10_2026

Investigation of Sulfur-related Influences on the Construction and Ring Opening of a Six-membered Cyclic Xanthate Derived from d‑Thymidine and CS₂ Autumn M. Andras (25311107) Nehal Fatima (25311110) Kai-Hua Mick Kuo (23627400) David K. Tran (9226281) Donald J. Darensbourg (1317624) Karen L. Wooley (1318485) Biophysics Biochemistry Medicine Cell Biology Neuroscience Evolutionary Biology Chemical Sciences not elsewhere classified Infectious Diseases unidirectional backbone compositional tof mass spectrometry three potential monomers supporting dft calculations mediated alternating vs fundamental advances extend ambient temperatures indicated minor regiorandom cleavages derived cyclic moieties upon subsequent rops nucleoside building blocks alternating c – >- fused configurations sustainable polymers derived membered bicyclic xanthate 2 </ sub c – >- fused derived polymers cyclic species polymers obtained connected polymers trans </ n </ co </ cis </ yield stereo thionocarbonate functionalities synthetic precursors succeeding cyclization structural similarity structural regioregularity structural characterization rops conducted related influences opening polymerization nmr spectroscopy native dna monomer synthesis minor trithiocarbonate low yields carbon disulfide butenyl )- With an interest in sustainable polymers derived from nucleoside building blocks, d-thymidine and carbon disulfide (CS₂) were used as synthetic precursors to construct a <i>trans</i>-fused, 6,5-membered bicyclic xanthate, 3′,5′-cyclic <i>N</i>³-(3-butenyl)-d-thymidine <i>trans</i> xanthate, for ring-opening polymerization (ROP) to yield stereo- and regiochemically defined homopolymer analogs of nucleic acids bearing thiocarbonate backbones. Screenings for CS₂ insertion and succeeding cyclization to form the targeted monomer revealed two additional d-thymidine-derived cyclic moieties, including a xanthate and trithiocarbonate of <i>cis</i>-fused configurations, isolated in low yields. Therefore, ROP experiments using alkoxy-based initiators and organobase catalysts at room temperature and supporting DFT calculations for enthalpies of ring opening were extended to all three potential monomers, with only the <i>trans</i>-fused bicyclic xanthate undergoing ROP. Structural characterization by MALDI-TOF mass spectrometry and NMR spectroscopy of polymers obtained from ROPs of 3′,5′-cyclic <i>N</i>³-(3-butenyl)-d-thymidine <i>trans</i> xanthate conducted at or somewhat below ambient temperatures indicated the presence of linear and cyclic species having primarily dimeric 5′,5′-trithiocarbonate-<i>co</i>-3′,3′-thionocarbonate connectivities from an alternating C–S and C–O cleavage pathway. Other minor trithiocarbonate, xanthate, and thionocarbonate functionalities were proposed to arise from backbiting reactions and/or minor regiorandom cleavages. In contrast, ROPs conducted at reduced temperatures (≤ −20 or −40 °C depending on the organobase) achieved selective C–S cleavage to yield 3′,5′-xanthate-connected polymers of <i>N</i>³-(3-butenyl)-d-thymidine with more structural similarity to native DNA. These fundamental advances extend the breadth of nucleoside-derived polymers, emphasizing the influence of sulfur incorporation during monomer synthesis and upon subsequent ROPs, with outcomes being temperature-mediated alternating vs. unidirectional backbone compositional and structural regioregularity. 2026-10-05T00:00:00Z Dataset Dataset 10.1021/jacs.6c15290.s001 https://figshare.com/articles/dataset/Investigation_of_Sulfur-related_Influences_on_the_Construction_and_Ring_Opening_of_a_Six-membered_Cyclic_Xanthate_Derived_from_d_Thymidine_and_CS_sub_2_sub_/34068797 CC BY-NC 4.0