Selective Formation of Functionalized α-Quaternary Malononitriles toward 5,5-Disubstituted Pyrrolopyrimidinones
作者:Alan Whitehead、Yong Zhang、Jamie McCabe Dunn、Edward C. Sherer、Yu-hong Lam、John Stelmach、Aaron Sun、Melisa Shiroda、Robert K. Orr、Sherman T. Waddell、Subharekha Raghavan
DOI:10.1021/acs.orglett.7b01930
日期:2017.9.1
A modular, selective approach to complex α-tertiary substituted malononitriles is reported. The method takes advantage of β-ester-substituted α,α-dinitrile alkenes as highly reactive, chemoselective electrophiles for 1,4-additions with organometallic nucleophiles to produce functionally and sterically dense all-carbon quaternary centers. In the presence of a chiral ester auxiliary bearing an aromatic
catalyst-free decarboxylative amidation of α-ketoacids with aminesundermildconditions has been developed. Advantages of the new protocol include avoidance of metal catalysts and high levels of functional group tolerance. In addition, the reaction can be scaled up and shows high chemoselectivity. Preliminary mechanistic studies suggest that singlet oxygen, generated from oxygen under irradiation, is the key
An environmentally benign and efficient electrochemical synthesis of enaminones via a decarboxylativecoupling reaction of α-keto acids using n-Bu4NI as a redox catalyst and electrolyte under constant current electrolysis in an undivided cell is reported. A broad vinyl azide substrate scope and high functional group tolerance are observed. A gram-scale reaction further demonstrates the practicability
Photoinduced homolytic decarboxylative acylation/cyclization of unactivated alkenes with α-keto acid under external oxidant and photocatalyst free conditions: access to quinazolinone derivatives
作者:Bin Sun、Rongcheng Shi、Kesheng Zhang、Xiaoli Tang、Xiayue Shi、Jiayun Xu、Jin Yang、Can Jin
DOI:10.1039/d1cc02415a
日期:——
A novel and green strategy for the synthesis of acylated quinazolinone derivatives via photo-induced decarboxylative cascade radical acylation/cyclization of quinazolinone bearing unactivated alkenes has been developed. The protocol provides a novel route to access acyl radicals from α-keto acids through a self-catalyzed energy transfer process. Most importantly, the reaction proceeded smoothly without
An evaluation of the substrate specificity and asymmetric synthesis potential of the cloned <scp>L</scp>-lactate dehydrogenase from <i>Bacillus</i><i>stearothermophilus</i>
作者:Daniel Bur、Marcel A. Luyten、Hla Wynn、Louis R. Provencher、J. Bryan Jones、Marvin Gold、James D. Friesen、Anthony R. Clarke、J. John Holbrook
DOI:10.1139/v89-161
日期:1989.6.1
assure its plentiful supply. Its specificity for keto acid substrates possessing straight- and branched-chain alkyl, cyclopropyl, or phenyl groups has been evaluated in preparative and kinetic terms, and compared with that of the mammalian pig heart enzyme (PHLDH). The specificities of BSLDH and PHLDH are similar, with branched alkyl-chain keto acids being poor substrates for both enzymes. Keywords: enzymes