Asymmetric Suzuki Cross-Couplings of Activated Secondary Alkyl Electrophiles: Arylations of Racemic α-Chloroamides
摘要:
A nickel-catalyzed stereoconvergent method for the enantioselective Suzuki arylation of racemic alpha-chloroamides has been developed. This process provides a unique example of an asymmetric arylation of an alpha-haloamide, an enantioselective arylation of an alpha-chlorocarbonyl compound, and an asymmetric Suzuki reaction with an activated alkyl electrophile or an arylboron reagent. The method is also applicable to the corresponding enantioselective cross-coupling of alpha-bromoamides. The coupling products can be transformed without racemization into enantio-enriched alpha-arylcarboxylic acids and primary alcohols. A modest kinetic resolution of the alpha-chloroamide was observed; a mechanistic study indicated that the selectivity may reflect discrimination by the chiral catalyst of the two enantiomeric alpha-chloroamides in an irreversible oxidative-addition process.
Efficient α-chlorination of carbonyl containing compounds under basic conditions using methyl chlorosulfate
作者:Saúl Silva、Christopher D. Maycock
DOI:10.1016/j.tetlet.2018.02.036
日期:2018.3
An efficient method for the α-chlorination of ketonesunder basic conditions is described using methyl chlorosulfate. Its applicability for the chlorination of other functional groups has also been studied and it is equally useful for the synthesis of α-chloroesters and amides. Methyl chlorosulfate is described for the first time as a positive chlorine source. Some aldol reactions which occur during
A Metallaphotoredox Strategy for the Cross‐Electrophile Coupling of α‐Chloro Carbonyls with Aryl Halides
作者:Tiffany Q. Chen、David W. C. MacMillan
DOI:10.1002/anie.201909072
日期:2019.10.7
effective for a wide variety of aryl bromide coupling partners, is predicated upon a halogen atom abstraction/nickel radical-capture mechanism that is generically successful across an extensive range of carbonyl substrates. The construction and use of arylacetic acid products have further enabled two-step protocols for the delivery of valuable building blocks for medicinal chemistry, such as aryldifluoromethyl
Method for the Production of D,L-2-Hydroxy-4-Alkylthio Butyric Acid
申请人:Deck Patrick
公开号:US20090318715A1
公开(公告)日:2009-12-24
The present invention relates to a process for preparing compounds of the formula (I)
by reacting compounds of the formula (II)
with thiolates (RS)
n
M.
The present invention further relates to a process for preparing compounds of the formula (II) from γ-butyrolactone.