Alkali Metal Alkoxides in Noyori‐Type Hydrogenations

Quaternary salt Ia reacts with sodium and lithium alkoxides to give 1-phenyl-1,4-dihydropyridine (IIIa) together with unsaturated aldehyde IVa. The reaction mechanism for formation of compound IVa from the primarily arising 2-alkoxy-1-phenyl-1,2-dihydropyridines is suggested on the basis of products IIIb and IVb, arising from the 3,4,5-trideuterio precursor Ib.

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Synthesis, structures and reduction chemistry of monophthalocyanine scandium hydroxides

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424619501992 ◽

2019 ◽

Vol 23 (11n12) ◽

pp. 1592-1602 ◽

Cited By ~ 1

Author(s):

Yumeela Ganga-Sah ◽

Elahe Tajbakhsh ◽

Rachel H. Platel ◽

Wen Zhou ◽

Daniel B. Leznoff

Keyword(s):

Alkali Metal ◽

Dihedral Angles ◽

Ambient Atmosphere ◽

Metal Alkoxides ◽

Metal Free ◽

H Nmr ◽

Vis Spectroscopy ◽

Hydrolysis Of ◽

Direct Hydrolysis

The preparation and structural characterization of a pair of scandium(III) phthalocyanine hydroxide complexes were achieved by reaction of PcScCl with alkali metal alkoxides, likely via hydrolysis of soluble PcSc-alkoxide intermediates. A Sc[Formula: see text]Li[Formula: see text]-OH)[Formula: see text] cubane supported by two distorted Pc rings of the form (PcSc)[Formula: see text]-OH)[Formula: see text]Li[Formula: see text](THF)(DME) was isolated from the reaction of PcScCl with LiO[Formula: see text]Pr, while a simpler alkali-metal-free [Pc[Formula: see text]Sc[Formula: see text]-OH)[Formula: see text](THF)] was obtained from addition of NaO[Formula: see text]Bu; both structures are reminiscent of bent metallocenes, with dihedral angles between the two Pc rings of 50.8 and 37.7[Formula: see text]respectively. A soluble PcScOH material can also be obtained directly via hydrolysis of insoluble PcScCl in approximately 95:5 THF:water. Reduction of the Pc ring of PcScCl using KC[Formula: see text] is reversible and generates Pc[Formula: see text] and Pc[Formula: see text]-containing materials that were characterized via UV-vis spectroscopy and, where appropriate EPR and [Formula: see text]H NMR spectroscopy; analogous reductions of the PcScOH-based species were irreversible. Exposure of the air-sensitive, reduced PcScCl-based species to ambient atmosphere generated PcScOH materials analogous to the direct hydrolysis route.

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ChemInform Abstract: Alkynylhalocarbenes. Part 3. Synthesis of 2-(Alk-1-ynyl)oxiranes from 1,1-Dichloroalk-2-ynes and 3-Substituted 3-Bromo-1,1,1-trichloropropanes under the Action of Potassium tert-Butoxide in the Presence of Alkali Metal Alkoxides.

ChemInform ◽

10.1002/chin.199837111 ◽

2010 ◽

Vol 29 (37) ◽

pp. no-no

Author(s):

K. N. SHAVRIN ◽

V. D. GVOZDEV ◽

O. M. NEFEDOV

Keyword(s):

Alkali Metal ◽

Metal Alkoxides

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