33026-24-3Relevant articles and documents
Synthesis of silaoxazolinium salts bearing weakly coordinating anions: Structures and catalytic activities in the aldol reaction
Chandra Sheker Reddy, Anugu,Chen, Zhang,Hatanaka, Tohru,Minami, Tatsuya,Hatanaka, Yasuo
, p. 3575 - 3582 (2013/07/26)
The synthesis and structures of silaoxazolinium salts 2 and their application to the catalytic Mukaiyama aldol reaction are described. The reaction of (N-amidomethyl)dimethylchlorosilane (1a) or (N-amidomethyl) bis(trimethylsilyl)chlorosilane (1b) with me
Reformatsky Reaction in Water: Evidence for a Radical Chain Process
Bieber, Lothar W.,Malvestiti, Ivani,Storch, Elisabeth C.
, p. 9061 - 9064 (2007/10/03)
The Reformatsky reaction of 2-bromo esters and carbonyl compounds in the presence of zinc can be carried out in concentrated aqueous salt solutions without any cosolvent. The reaction of bromoacetates is greatly enhanced by catalytic amounts of benzoyl peroxide or peracids and gives satisfactory yields with aromatic aldehydes. Preparative yields comparable to those of the traditional procedure are obtained with ethyl 2-bromoisobutyrate. This ester needs no catalyst and reacts even with saturated aldehydes and aromatic ketones, although in low yields. A radical chain mechanism, initiated by electron abstraction from the organometallic Reformatsky reagent, is proposed. Two nonchain pathways, involving radicals directly produced on the metal surface, may compete, especially in the case of secondary and tertiary halides.
Steric and Electronic Effects on the Photochemical Reactivity of Oxime Acetates of β,γ-Unsaturated Aldehydes
Armesto, Diego,Horspool, William M.,Gallego, Mar G.,Agarrabeitia, Antonia R.
, p. 163 - 170 (2007/10/02)
A general synthesis of 5-unsubstituted N-acetoxy 3,3-dimethyl-1-azapenta-1,4-dienes starting from 2-(1,3-dithian-2-yl)-2-methylpropanal is described.The influence of 5-phenyl, 4-phenyl, 5-cyclohexyl, 5-tert-butoxycarbonyl and 5,5-dicyclohexyl substitution on the outcome of the photochemical reactions of the oxime acetates of β,γ-unsaturated aldehydes has been studied with a view to proving or disproving the operation of a deactivating free rotor in the aza-di-?-methane rearrangement.The results obtained show that if the radical formed at C-5 can be stabilized by conjugation with an aryl group or by certain types of disubstitution then the aza-di-?-methane rearrangement takes place successfully.In any other situation the reaction fails.These results clearly show that the free rotor effect is not responsible for the failure of C-5 monosubstituted 1-aza-1,4-dienes to undergo the aza-di-?-methane rearrangement.
