Iodine-Mediated Direct Generation of <i>o</i>
-Quinone Methides at Room Temperature: A Facile Protocol for the Synthesis of <i>ortho</i>
-Hydroxybenzyl Thioethers
作者:R. Sidick Basha、Chia-Wei Chen、Daggula Mallikarjuna Reddy、Chin-Fa Lee
DOI:10.1002/asia.201800233
日期:2018.9.4
An iodine‐mediated preparation of ortho‐quinonemethides (o‐QMs) from ortho‐hydroxybenzylalcohols by a C−O bond scission strategy is described. The in situ generated o‐QMs were then employed for C−S bond formation by thio‐Michael addition of thiols to provide the ortho‐hydroxybenzyl thioethers (o‐HBT) in moderate to excellent yields.
concerning a fast conformational change of the six-membered metallacycle. DOSY (Diffusion Ordered SpectroscopY) 1H experiments and ligand scrambling strongly suggested that complexes 1–6 exist as dimeric species in solution. All complexes were active as catalysts in the ring-opening polymerization of cyclic esters. In particular, magnesium complexes showed superior ε-caprolactone and lactide ROP behavior
Imidotungsten(VI) complexes with chelating phenols as ROMP catalysts
作者:Juuso Hakala、Mikko M. Hänninen、Ari Lehtonen
DOI:10.1016/j.inoche.2011.05.021
日期:2011.9
Tungsten(VI) complexes of the type [W(NPh)Cl3(L)] (L = chelating phenolate) were studied as catalyst precursors for ROMP of 2-norbornene, dicyclopentadiene and 5-vinyl-2-norbornene. These compounds form active catalysts when treated by ethyl magnesium bromide. Moreover, polymerisations can be run under ambient atmosphere without complicated inert atmosphere techniques. Synthesis and crystalstructure of a
Spectacular platinum(0): 1,2‐Oxaplatinacycles 2 were formed unexpectedly from 2‐hydroxybenzyl sulfide derivatives 1 by bond cleavage mediated by platinum(0) (see scheme; nb=norbornene). The thermal reaction of 2 gave novel six‐membered 1,2,3‐oxaphosphaplatinacycles through ring expansion accompanied by the insertion of a phosphorus atom into the PtO bond and the 1,2‐shift of a phenyl group.
壮观铂(0):1,2- Oxaplatinacycles 2是从2-羟基苄基硫醚衍生物出人意料地形成1由铂(0)介导的键裂解(参见方案; NB =降冰片烯)。的热反应2得到通过扩环伴随磷原子到的Pt的插入新颖六元1,2,3- oxaphosphaplatinacycles O键和苯基的1,2-移位。
Phenoxy-Thioether Aluminum Complexes as ε-Caprolactone and Lactide Polymerization Catalysts
readily react with 1 equiv of AlMe3 to afford the corresponding Al chelate complexes 4,6-tBu2-OC6H2-2-CH2S(2-R-C6H4)}AlMe2 (R = H (1), Br (2), CH3 (3), CF3 (4)) in quantitative yields. All the aluminum methylcomplexes are stable monomeric species. In the solid state, as determined from X-ray crystallographicstudies, complex 2 consists of a four-coordinate aluminum species in which the metal center