18111-10-9

Upstream product

• 86-81-7 3,4,5-trimethoxy-benzaldehyde 
• 105-36-2 ethyl bromoacetate 
• 4071-88-9 trimethylsilanyl-acetic acid ethyl ester 
• 3044-56-2 ethyl trimethoxybenzoyl acetate 

Relevant academic research and scientific papers

Bu 4 N + -Controlled Addition and Olefination with Ethyl 2-(Trimethylsilyl)acetate via Silicon Activation

Catalytic Bu 4 NOAc as silicon activator of ethyl 2-(trimethylsilyl)acetate, in THF, was utilized for the synthesis of β-hydroxy esters, whereas employing catalytic Bu 4 NOTMS gave α,β-unsaturated esters. The established reaction conditions were applicable to a diverse range of aromatic, heteroaromatic, aliphatic aldehydes and ketones. Reactions were achieved at room temperature without taking any of the specialized precautions that are in place for other organometallics. A stepwise olefination pathway via silylated β-hydroxy esters with subsequent elimination to form the α,β-unsaturated ester has been demonstrated. The key to selective product formation lies in use of the weaker acetate activator which suppresses subsequent elimination whereas stronger TMSO - activator (and base) facilitates both addition and elimination steps. The use of tetrabutyl ammonium salts for both acetate and trimethylsilyloxide activators provide enhanced silicon activation when compared to their inorganic cation counterparts.

Versatile iridicycle catalysts for highly efficient and chemoselective transfer hydrogenation of carbonyl compounds in water

Cyclometalated iridium complexes are shown to be highly efficient and chemoselective catalysts for the transfer hydrogenation of a wide range of carbonyl groups with formic acid in water. Examples include α-substituted ketones (α-ether, α-halo, α-hydroxy, α-amino, α-nitrile or α-ester), α-keto esters, β-keto esters and α,β-unsaturated aldehydes. The reduction was carried out at substrate/catalyst ratios of up to 50000 at pH 4.5 and required no organic solvent. The protocol provides a practical, easy and efficient way for the synthesis of β-functionalised secondary alcohols, such as β-hydroxyethers, β-hydroxyamines and β-hydroxyhalo compounds, which are valuable intermediates in pharmaceutical, fine chemical, perfume and agrochemical synthesis. Water wonder: Iridicycle catalysts are versatile and allow the highly efficient and chemoselective transfer hydrogenation of a variety of carbonyl compounds, including problematic and challenging ones, with formate in neat water (see scheme).

Convenient preparation of metals deposited on solid supports and their use in organic synthesis

'High-surface alkali metals' can be conveniently prepared via deposition of corresponding metals on various supports such as sodium chloride, polyethylene, polypropylene and cross-linked polystyrene from their solutions in liquid ammonia. Alkali metals deposited on polymeric supports can be stored in form of stable suspensions in inert solvents and used for the acyloin and Dieckmann condensations and for preparation of organolithiums. Addition of the suspension of supported alkali metal to a solution of zinc chloride gave an active zinc on polymeric support, which can be used for the Reformatski and Barbier reactions.

Active metals prepared in liquid ammonia. Zinc and tin-promoted synthesis of β-hydroxyesters, homoallylic and homopropargylic alcohols

Active zinc and tin provider can be prepared by reduction of ZnCl2 and SnCl2 with sodium in tetrahydrofuran-liquid ammonia mixtures of various compositions. The activity of the reduced zinc depends on concentration of ammonia in the reactors medium Zinc(A) prepared in liquid ammonia (Method A) was much less active then zinc (B) prepared in THF containing 10-20 volume% of liquid ammonia (Method B). The X-ray powder difractiometry data suggested that zinc (H) was less crystalline then zinc (A). The Reformatsky and Barbier type reactions of carbonyl compounds with α-bromoesters, allylic and propargylic bromides in the presence of Zn or Sn prepared by method B gave the corresponding β-hydroxyesters, homollylic and homopropargylic alcohols in good to excellent yields.