skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Tungsten oxo alkylidene complexes for Zselective olefin metathesis

Abstract

The current application describes tungsten oxo alkylidene complexes for olefin metathesis.

Inventors:
; ;
Publication Date:
Research Org.:
Massachusetts Institute of Technology, Cambridge, MA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1289876
Patent Number(s):
9,409,938
Application Number:
14/797,848
Assignee:
Massachusetts Institute of Technology (Cambridge, MA) CHO
DOE Contract Number:
FG02-86ER13564
Resource Type:
Patent
Resource Relation:
Patent File Date: 2015 Jul 13
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Schrock, Richard Royce, Peryshkov, Dmitry Vyacheslavovich, and Hoveyda, Amir H. Tungsten oxo alkylidene complexes for Zselective olefin metathesis. United States: N. p., 2016. Web.
Schrock, Richard Royce, Peryshkov, Dmitry Vyacheslavovich, & Hoveyda, Amir H. Tungsten oxo alkylidene complexes for Zselective olefin metathesis. United States.
Schrock, Richard Royce, Peryshkov, Dmitry Vyacheslavovich, and Hoveyda, Amir H. Tue . "Tungsten oxo alkylidene complexes for Zselective olefin metathesis". United States. doi:. https://www.osti.gov/servlets/purl/1289876.
@article{osti_1289876,
title = {Tungsten oxo alkylidene complexes for Zselective olefin metathesis},
author = {Schrock, Richard Royce and Peryshkov, Dmitry Vyacheslavovich and Hoveyda, Amir H.},
abstractNote = {The current application describes tungsten oxo alkylidene complexes for olefin metathesis.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Aug 09 00:00:00 EDT 2016},
month = {Tue Aug 09 00:00:00 EDT 2016}
}

Patent:

Save / Share:
  • The current application describes tungsten oxo alkylidene complexes for olefin metathesis.
  • An alternative synthesis of W(CH-t-Bu)(NAr)(dme)Cl{sub 2} (Ar = 2,6-C{sub 6}-H{sub 3}-i-Pr{sub 2}) consists of the five steps WCl{sub 6} {yields} W(O)Cl{sub 4} {yields} W(NAr)Cl{sub 4} {yields} W(NAr)(O-t-Bu){sub 2}Cl{sub 2}(THF) {yields} W(NAr)(O-t-Bu){sub 2}(CH{sub 2}-t-Bu){sub 2} {yields} W(CH-t-Bu)(NAr)(dme)Cl{sub 2}, in which tert-butoxide protecting groups are replaced by chlorides in the last step upon addition of PCl{sub 5}. The easiest synthesis to a catalyst precursor consists of the three steps WO{sub 2}Cl{sub 2} {yields} W(NAr){sub 2}Cl{sub 2}(dme) {yields} W(NAr){sub 2}(CH{sub 2}R){sub 2} {yields} W(CHR)(NAr)(OTf){sub 2}(dme) (R = t-Bu, CMe{sub 2}Ph; OTf = OSO{sub 2}CF{sub 3}), in which an imido ligand protecting group ismore » ultimately replaced by two triflate ligands upon addition of triflic acid in the last step. An X-ray study of W(CH-t-Bu)(NAr)(O-t-Bu){sub 2} shows it to be a pseudotetrahedral complex in which the tert-butyl group points toward the imido ligand.« less
  • No abstract prepared.
  • Addition of LiDIPP = O-2,6-C{sub 6}H{sub 3}-i-Pr{sub 2} to Ta(CH-t-Bu)(THF){sub 2}Cl{sub 3} yields Ta(CH-t-Bu)(DIPP){sub 3}(THF) (1) in high yield. Ta(CH-t-Bu)(DMP){sub 3}(THF) (3; DMP = O-2,6-C{sub 6}H{sub 3}Me{sub 2}) and Ta(CH-t-Bu)(TIPT){sub 3}(THF) (5; TIPT = S-,2,4,6-C{sub 6}H{sub 2}i-Pr{sub 3}) can be prepared by analogous methods. 1 reacts rapidly with 1 equiv of styrene to give the tantalacyclobutane complex Ta(CH(Ph)CH(t-Bu)CH{sub 2})(DIPP){sub 3}. The crystal and molecular structure of the complex are reported. An analogous reaction between 1 and vinyltrimethylsilane gives Ta(CHSiMe{sub 3})(DIPP){sub 3}(THF) or Ta(CH(SiMe{sub 3})CH(SiMe{sub 3})CH{sub 2})(DIPP){sub 3} depending upon reaction conditions; the two are in ready equilibrium. 1 reacts smoothlymore » with ethylene to give Ta(CH{sub 2}CH{sub 2}CH{sub 2})(DIPP){sub 3} in high yield, but treatment of 1 with olefins such as propylene or 1-butene did not lead to any characterizable species. Addition of excess cis-2-pentene to 1 results in rapid metathesis (100 equiv to equilibrium in < 15 min), but activity is short-lived. In contrast to reactions between 1 and olefins, Ta(CH-t-Bu)(TIPT){sub 3}(THF) does not react with ordinary olefins and will not metathesize them. Tantalacyclobutane complexes containing the DIPP ligand react with the carbonyl functionality to give a mixture of insertion chemistry (oxytantalacyclohexane complexes) and Wittig-like reactivity, depending upon the carbonyl compound, the tantalacycle, and the temperature. 1 reacts with norbornene to give an isolable tantalacyclobutane complex, Ta(CH(C{sub 5}H{sub 8})CHCH(t-Bu))(DIPP){sub 3}, whose crystal structure is reported. 25 references, 9 figures, 7 tables.« less
  • Neutron diffraction studies of the two title compounds in which precise hydrogen atom location was essential, have established that the neopentylidene ligands are highly distorted. In (Ta(CHCMe/sub 3/)(PMe/sub 3/)Cl/sub 3/)/sub 2/, the Ta==C/sub ..cap alpha../-C/sub ..beta../ is 161.2 (1)/sup 0/, the Ta==C/sub ..cap alpha../-H/sub ..cap alpha../ angle is 84.8 (2)/sup 0/, the Ta==C/sub ..cap alpha../ bond is short (1.898 (2) A), the C/sub ..cap alpha../-H/sub ..cap alpha../ distance is long (1.131 (3) A), and H/sub ..cap alpha../ angle is 78.1 (3)/sup 0/, the C/sub ..cap alpha../-H/sub ..cap alpha../ bond is also long (1.135 (5) A), the Ta==C/sub ..cap alpha../ bondmore » length short (1.946 (3) A), and H/sub ..cap alpha../ is only 2.042 (5) A from Ta. We believe the neopentylidene ligand is distorted in each case primarily because the metal is attracting electron density from the C/sub ..cap alpha../-H/sub ..cap alpha../ bond. The tantalum-ethylene bonding in the second molecule is best described as that of a tantallacyclopropane ring on the basis of the long ethylene C-C bond (1.477 (4) A) and the large angle (68.5/sup 0/) between the normals to the two CH/sub 2/ planes. We believe the neopentylidene/ethylene complex does not decompose via a tantallacyclobutane complex because of the large separation between the neopentylidene and ethylene ligands.« less