98273-79-1Relevant academic research and scientific papers
Spin-Center Shift-Enabled Direct Enantioselective α-Benzylation of Aldehydes with Alcohols
Nacsa, Eric D.,MacMillan, David W. C.
supporting information, p. 3322 - 3330 (2018/03/13)
Nature routinely engages alcohols as leaving groups, as DNA biosynthesis relies on the removal of water from ribonucleoside diphosphates by a radical-mediated "spin-center shift" (SCS) mechanism. Alcohols, however, remain underused as alkylating agents in synthetic chemistry due to their low reactivity in two-electron pathways. We report herein an enantioselective α-benzylation of aldehydes using alcohols as alkylating agents based on the mechanistic principle of spin-center shift. This strategy harnesses the dual activation modes of photoredox and organocatalysis, engaging the alcohol by SCS and capturing the resulting benzylic radical with a catalytically generated enamine. Mechanistic studies provide evidence for SCS as a key elementary step, identify the origins of competing reactions, and enable improvements in chemoselectivity by rational photocatalyst design.
Synthesis of regioisomeric pyrido[c]azocanones from azaindanone derivatives
Penning, Miriam,Christoffers, Jens
, p. 2140 - 2149 (2014/04/17)
A ring enlargement reaction with methylamine gave new pyrido[2,3-c]-, pyrido[3,4-c]- and pyrido[3,2-c]azocanone derivatives from cyclic β-oxo esters with a cyclopentapyridine skeleton and a 1,4-diketone moiety. The starting materials for this ring transformation were either prepared from halogenopyridine carboxylates by Heck reaction and subsequent hydrogenation, or (halogenomethyl)pyridine carboxylates were submitted to SN reaction with diethyl malonate. Both routes were completed by Dieckmann condensation to build the cyclic β-oxo ester structure and alkylation with phenacylbromide to install the 1,4-diketone motif. Copyright
FUSED HETEROARYL MODULATORS OF GLUCOCORTICOID RECEPTOR, AP-1, AND/OR NF-KB ACTIVITY AND USE THEREOF
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Page/Page column 70, (2009/10/09)
Novel non-steroidal compounds are provided which are useful in treating diseases or disorders associated with modulation of the glucocorticoid receptor, AP-1, and/or NF-κB activity, including metabolic and inflammatory and immune diseases or disorders, ha
Application of organolithium compounds in organic synthesis. Part 19. Synthetic strategies based on aromatic metallation. A concise regiospecific synthesis of 3-halogenated picolinic and isonicotinic acids
Epsztajn,Plotka,Grabowska
, p. 1075 - 1086 (2007/10/03)
The synthesis of the halogenated picolin- and isonicotinalides (3) and (4) via metallation (n-BuLi) of the anilides (1) and (2) and then the reaction of the generated bis-lithiated anilides with halogenating agents (CCl3-CCl3, CH2Br-CH2Br, I2) followed by subsequent acidic hydrolysis of (3) and (4), as a way of regiospecific transformation of picoline and isonicotine acids into their C3-halogenated derivatives, is described.
Synthesis of regioisomeric 6,9-(chlorofluoro)-substituted benzo[g]quinoline-5,10-diones, benzo[g]isoquinoline-5,10-diones and 6-chloro-9-fluorobenzo[g]quinoxaline-5,10-dione
Krapcho, A. Paul,Gallagher, Cynthia E.,Hammach, Abdelhakim,Ellis, Michael,Menta, Ernesto,Oliva, Ambrogio
, p. 27 - 32 (2007/10/03)
Treatment of difluoro or chloro fluoro-substituted benzyl bromides 5a-c with zinc dust in tetrahydrofuran leads to the corresponding benzylic zinc bromides 6a-c. These organometallics on treatment with chlorosubstituted heterocyclic esters 4A and 4B mediated by nickel catalysis undergo couplings to yield dihalobenzyl substituted heterocyclic esters 7Aa-c and 7Ba-c. Treatment of 4c with 6c under Pd catalysis leads to 7Cc. The acids 8, prepared by hydrolysis of these esters, with treatment of fuming sulfuric acid undergo cyclizations and oxidations to yield the desired regioisomeric dihalo-substituted heterocyclic quinones 2.
