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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. 2016. "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 = 2016,
month = 8
}

Patent:

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  • 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