104426-40-6Relevant articles and documents
Sulfur-mediated difunctionalization of internal and terminal alkynes for the synthesis of α-acetoxy ketones
Li, Pingfan,Zhang, Zhong
, (2020/02/13)
The sulfur-mediated difunctionalization of alkynes is reported to give α-acetoxy ketones in a one-pot operation under mild conditions with 19–92% yield. By using wet potassium acetate as both the aqueous base and nucleophilic reagent, both terminal alkynes and internal alkynes could be converted into the α-acetoxy ketone products.
Preparation and Reactivity of Highly Functionalized Organometallics at the α Position of Oxygen or Nitrogen
Knochel, Paul,Chou, Tso-Sheng,Jubert, Carole,Rajagopal, Duddu
, p. 588 - 599 (2007/10/02)
α-Halogenoalkyl carboxylates (FG-R1CH(X)(OCOR2); FG = COOR, CN, SR; X = I, Br) were readily prepared by the addition of an acid chloride or bromide (R2COX; X = Br or Cl) to an aldehyde (FG-RCHO) in the presence of a catalytic amount of ZnCl2.They insert efficiently zinc dust in THF-DMSO (X = Br, 8 - 10 deg C, 6 - 10 h) affording the corresponding zinc organometallics at the α position to oxygen FG-RCH(ZnBr)(OAc).After the addition of the THF-soluble copper salt CuCN*2LiCl, the corresponding copper reagents FG-RCH(Cu(CN)ZnBr)(OAc) are formed and reacted with variousclasses of electrophiles such as acid chlorides, aldehydes, enones, allylic and alkynyl halides, activated alkynes, nitro olefins and alkylidenemalonates providing polyfunctional molecules in excellent yields.Similarly, zinc organometallics at the α position to the nitrogen of cyclic imides were prepared by the zinc insertion to cyclic α-chloromethyl (or α-chloroethyl) imides.After their transmetalation to the corresponding copper organometallic ((R1CO)2NCH(R)(Cu(CN)ZnCl); R = Me or H), they were reacted with allylic and alkynyl halides and ethyl propiolate affording polyfunctional imides.The reaction of cyclic N-(chloromethyl)imides with aldehydes in the presence of chromium(II) chloride in THF furnishes protected amino alcohols in 36 - 95percent yield.
A General Preparation of Highly Functionalized Zinc and Copper Organometallics at the α-Position to an Oxygen
Chou, Tso-Sheng,Knochel, Paul
, p. 4791 - 4793 (2007/10/02)
α-Bromoalkyl acetates 2, which are readily prepared by the addition of acetyl bromide to aldehydes, insert zinc under mild conditions affording, after the addition of CuCN*2LiCl, polyfunctional α-acetoxy copper reagents of type 1.Their reactivity toward various organic electrophiles is described.
Medium-ring Ketone Synthesis. Intramolecular Acylation of Sulfur-stabilized Carbanions: A Model Study
Ohtsuka, Yasuo,Oishi, Takeshi
, p. 443 - 453 (2007/10/02)
Intramolecular acylation of the sulfur-stabilized carbanions of the acyclic ester 9 and amide sulfides 11 was carried out as a model study for developing an effective method for the construction of medium-ring ketones by ring closure.Reaction of 9a-c or 11a-g with lithium diisopropylamide (LDA) proceeded smoothly and the expected keto sulfides 10a-c or 12a-g, respectively, were obtained.In the cases where R1 and/or R2 in 11 were normal alkyl groups, the reaction did not take place.However, these difficulties were readily overcome either by introducing a methyl group next to the carbonyl group or by converting the sulfides into the corresponding sulfoxides or sulfones.Acylation in the allyl sulfides 11b, d, f and the allyl sulfone 20b takes place at the α-position to the sulfur atom, yielding β,γ-unsaturated ketones.A reductive removal of the sulfide moiety or its conversion into other functional groups was also examined.
