Metallacyclobutanes from central carbon alkylation of early metal .eta.3-allyl complexes. Nucleophilic additions to cationic, Lewis base-free zirconium and titanium permethylmetallocene .eta.3-allyl complexes

New Chiral Lanthanide Amide Ate Complexes for the Catalysed Synthesis of Scalemic Nitrogen‐Containing Heterocycles

“…Anhydrous YbCl 3 and YCl 3 and (R)-(+)-1,1'-binaphthyl-2,2'-diamine were purchased. Compounds Y[NA C H T U N G T R E N N U N G (tms) 2 ] 3 , [26] (R)-(+)-2,2'-Bis(cyclopentylamino)-1,1'-binaphthyl, [27] and Ph 2 CHK [28] were prepared according to reported procedures. The bis(N-neopentyl)binaphthylamine ligand and the complex Li…”

Cationic Organozirconium and Organohafnium Complexes

“…This reaction is general for R = alkyl, allyl, or benzyl, and has been employed in the synthesis o f many complexes (as [BPh 4 ]~ salts) including [Zr(Me)(THF)Cp' 2 ] + (Cp' = Cp (2), C 5 H 4 Me (3), Cp* (4)), 5 ' 6 or [Zr(Me)(THF)({r|-C 5 H 4 } 2 SiMe,)] + (5), 7 [Zr(Bz)(THF)Cp' 2 ] + (Cp 1 = Cp (6) or C 5 H 4 Me (7)),* [Zr(Bz)(THF)(EBTHI)] + (8) (EBTHI = ethylenebis(tetrahydroindenyl)), 9 [Zr(Me)(THF)CpCp*] + (9), 7 [Hf(Me)(THF)Cp 2 ] + (10), 7 and [Zr(r) 3 -allyl)Cp* 2 ] + (II). 10 Oxidative cleavage o f M-Ph bonds does not occur readily under mild conditions; for example, no reaction is observed in the case of [Zr(Ph) 2 Cp 2 ]. n The dimethylferrocenium reagent [Fe(Tj-C 5 H 4 Me) 2 ][BPh4] is preferred over [FeCp 2 ][BPh 4 ] due to its greater thermal stability.…”

“…46 The reactions of the T| 3 -allyl complex (11) with organic nucleophiles have been described. 10 The bulky nucleophiles KCHPh 2 and KCH(Me)Ph add regioselectively to the allyl central carbon yielding neutral zirconacyclobutane complexes [Zr{ri 2 -CH 2 CH(R)CH 2 }Cp* 2 ] (R = CHPh 2 or CH(Me)Ph), whereas smaller nucleophiles such as MeMgCl, MeLi, and allyl Grignard reagents add to zirconium.…”

“…The base-free T| 3 -allyl complex(11) was prepared by reaction o f the "tuck-in" complex [Zr(r|allyl)(Ti 6 -C 5 Me 4 CH 2 )Cp*] with [HNEt 3 ][BPh 4 ] at low temperature (Equation(8)) 10. Complex(11)is also available by oxidation o f [Zr(r| 3 -allyl)(r| 1 -allyl)Cp* 2 ] with [Fe(r|-C 5 H 4 Me) 2 ][BPh 4 ] (Section 12.2.1.1).…”

Samarium Iodobinaphtholate: An Efficient Catalyst for Enantioselective Aza‐Michael Additions of O‐Benzylhydroxylamine to N‐Alkenoyloxazolidinones

“…Potassium diphenyl methide was prepared as described in the literawww.eurjoc.orgture. [26] N-Alkenoyl oxazolidinones were prepared as described in the literature. [27] The NMR spectroscopic data were recorded with 360, 300, and 250 spectrophotometers, operating at 360, 300, and 250 MHz for 1 H NMR and 90, 75, and 62.5 MHz for 13 C NMR.…”