Preparation of substituted transition-metal (η1-propargyl complexes and their [3+2] cycloaddition reactions with sulfur dioxide and disulfur monoxide. Transition-metal–carbon bond cleaving reactions of the cycloadducts which yield oxathiolene oxides and dithiolene oxides

Novel C–H activation and C–S formation reactions on disulfide and diselenide ligands in dinuclear ruthenium complexes

“…Recently, transition metal mediated [3 + 2] cycloadditions between allenyltype alkyne and disulfur oxide or sulfur dioxide have been reported and seem to be similar to our reactions (Scheme 10) [85]. Another example of [3 + 2] cycloaddition is the reaction of zwitterionic 1,3-dipoles, having nitrogen and/or oxygen rather than carbon, with alkenes or alkynes (Scheme 11) [86].…”

Recent chemistry of the η5-cyclopentadienyl dicarbonyl iron anion

“…Welker et al prepared [80] the Fp 1 -allylic complex (Fp-CH 2 -CH CH 2 ) and the Fp 1 -alkynylic complex (Fp-CH 2 -CCCH 3 ) by known procedures so they could be reacted with ketenes as a means to cyclopentenones. Welker et al utilized 2-propyne tosylate electrophiles to prepare [81][82][83][84] the corresponding Fp complexes (Scheme 20) for [3 + 2] cycloadditions with sulfur dioxide and sulfur trioxide. The iron-mediated complexes were employed as precursors to sulfur heterocycles such as sulfenate esters which are potential inhibitors of cancer and HIV type 1 replication.…”

Remote substituent effects on homolytic FeC bond energies of p‐G‐C6H4CH2Fe(CO)2(η5‐C5H5) and p‐G‐C6H4(H)(CN)CFe(CO)2(η5‐C5H5) studied by Hartree–Fock and density functional theory methods

“…It is clear that the FpC bond strengths exert a major influence on the properties of iron–carbon compounds, and a detailed knowledge of the factors that determine the FpC bond strengths would greatly aid in understanding reactivity patterns in many processes 13. For example, Fp compounds have been applied to preparing new anticarcinogenic enzyme inducers used to synthesize some cycloadducts along with Fp–carbon bond cleaving reactions to yield new heterocyclic compounds with biological activities 14…”