119092-92-1Relevant academic research and scientific papers
Rendering schrock-type molybdenum alkylidene complexes air stable: User-friendly precatalysts for alkene metathesis
Heppekausen, Johannes,Fuerstner, Alois
supporting information; experimental part, p. 7829 - 7832 (2011/10/05)
A matter of convenience: Schrock molybdenum alkylidenes are amongst the most powerful olefin metathesis catalysts known to date, but their sensitivity to air and moisture mandates their handling in a glove-box or by Schlenk techniques. This inconvenience is circumvented by using the corresponding phenanthroline- or bipyridine adducts, which are bench-stable and hence very user-friendly. The active species can be liberated from these precatalysts in uncompromised form on treatment with ZnCl2 in toluene (see scheme).
Sequential ring-closing metathesis/Pd-catalyzed, Si-assisted cross-coupling reactions: General synthesis of highly substituted unsaturated alcohols and medium-sized rings containing a 1,3-cis-cis diene unit
Denmark, Scott E.,Yang, Shyh-Ming
, p. 9695 - 9708 (2007/10/03)
A sequential ring-closing metathesis/silicon-assisted cross-coupling protocol has been developed. Alkenyldimethylsilyl ethers of allylic, homoallylic and bis(homoallylic) alcohols undergo facile ring closure with Schrock's catalyst to afford 5-, 6-, and 7-membered cycloalkenylsiloxanes, respectively, in some cases with substituents on both alkenyl carbons. These siloxanes are highly effective coupling partners that afford styrenes and dienes (with various aryl and alkenyl halides) in high yield and specificity as well as good functional group compatibility. The siloxanes bearing a Z-iodoalkenyl tether undergo an intramolecular coupling process in the presence of [allylPdCl] 2 which constitutes a powerful method for the construction of medium-sized rings with an internal 1,3-cis-cis diene unit. The formation of 9-, 10-, 11-, and 12-membered carbocyclic dienes is achieved in good yield. Extension to the synthesis of 9-membered ring unsaturated ethers has also been accomplished. Noteworthy features of this process include: (1) highly stereospecific intramolecular coupling, (2) flexible positioning of the revealed hydroxy group, and (3) potential extension to other medium-sized carbocycles and heterocycles. Graphical Abstract.
Sequential Ring-Closing Metathesis and Silicon-Assisted Cross-Coupling Reactions: Stereocontrolled Synthesis of Highly Substituted Unsaturated Alcohols
Denmark, Scott E.,Yang, Shyh-Ming
, p. 1749 - 1752 (2007/10/03)
(matrix presented) A sequential ring-closing metathesis/silicon-assisted cross-coupling sequence has been developed. Alkenyldimethylsilyl ethers of ω-unsaturated alcohols undergo facile ring closure with Schrock's catalyst to afford five-, six-, and seven
