59142-62-0Relevant academic research and scientific papers
Synthesis of Cyclopropanoids via Substrate-Based Cyclization Pathways
Mishra, Uttam K.,Patel, Kaushalendra,Ramasastry
supporting information, p. 175 - 179 (2019/01/04)
A series of unexpected reactions triggered by the dimethyloxosulfonium methylide led to the discovery of unconventional approaches for the synthesis of cyclopropa-fused tetralones and indeno-spirocyclopropanes. These highly functionalized structures were further elaborated in one step to privileged scaffolds such as tetralones, indenones, and fluorenones. As a whole, the results presented herein establish new diversity-oriented folding pathways.
Substitution controlled functionalization of ortho -bromobenzylic alcohols via palladium catalysis: Synthesis of chromenes and indenols
Mahendar, Lodi,Satyanarayana, Gedu
supporting information, p. 2059 - 2074 (2014/04/03)
An efficient domino Pd-catalyzed transformation of simple ortho-bromobenzyl tertiary alcohols to chromenes is presented. Their formation is believed to proceed via the formation of a five-membered palladacycle, which, in turn, involves in an intermolecular homocoupling with the second ortho- bromobenzyltertiary alcohol to yield the homo-biaryl bond followed by intramolecular C-O bond formation. Interestingly, when there is an allylic substituent on the benzylic carbon atom, a chemoselective switch was observed, which preferred intramolecular Heck coupling and gave indenols. Further, it has been confirmed that the tertiary alcohol functionality is indispensible to give the coupled products, whereas the use of primary/secondary benzylic alcohols furnished the simple carbonyl products via a possible reductive debromination followed by oxidation due to the availability of β-hydrogen(s).
Fluorenone synthesis by palladacycle-catalyzed sequential reactions of 2-bromobenzaldehydes with arylboronic acids
Liu, Tao-Ping,Liao, Yuan-Xi,Xing, Chun-Hui,Hu, Qiao-Sheng
supporting information; experimental part, p. 2452 - 2455 (2011/06/25)
Chemical equations presented. A new, anionic four-electron donor-based (type I) palladacycle-catalyzed sequential reaction of 2-bromobenzaldehydes with arylboronic acids based on the addition reaction, cyclization via C-H activation-oxidation sequence is described. Our study provided an efficient access to a variety of substituted fluorenones/indenofluorenediones from readily available arylboronic acids and 2-bromobenzaldehydes.
Photoinduced C-Br homolysis of 2-bromobenzophenones and Pschorr ring closure of 2-aroylaryl radicals to fluorenones
Moorthy, Jarugu Narasimha,Samanta, Subhas
, p. 9786 - 9789 (2008/03/17)
(Chemical Equation Presented) A variety of diversely substituted 2-aroylaryl radicals, generated by photoinduced homolysis of 2-bromoarylketones, is shown to undergo Pschorr cyclization to yield fluorenones in moderate to excellent yields. The photochemical results illustrate that the substituents in the two phenyl rings of the 2-bromobenzophenone skeleton exert a dramatic influence on the reactivity of the derived 2-aroylaryl radicals. The disubstitution by methoxy groups in the radical ring renders the aryl σ-radical highly electrophilic and unreactive for hydrogen abstraction and cyclization. On the other hand, the substituents in the non-radical ring that strongly stabilize the hydrofluorenyl π-radical, formed subsequent to the attack of the 2-aroylaryl radical on the non-radical ring, promote cyclization to furnish fluorenones in excellent isolated yields.
Orthobromodiphenylmethane derivatives as starting materials for the total synthesis of anthraquinones
Almeida, Wanda P.,Costa, Paulo R.R.
, p. 4507 - 4518 (2007/10/03)
In this communication we describe the synthesis of four simple anthraquinones by a five-step sequence, using easily available bromobenzaldehydes and phenyllithium derivatives as starting materials.
Synthesis of spiro[isobenzofuran 1(3H),4' piperidines] as potential central nervous system agents
Bauer,Duffy,Hoffman,Klioze,Kosley Jr.,McFadden,Martin,Ong
, p. 1315 - 1324 (2007/10/05)
Synthesis of 1' methyl 3 phenylspiro[isobenzofuran 1(3H),4' piperidine] (7a, HP 365) and the demethyl analogue 9a (HP 505) was prompted by recognition of an aminoalkyl(aryl)isobenzofuran moiety common to the antidepressants talopram (Lu 3-010) and trans 10,11 dihydro 5,10 epoxy 5 [3 (methylamino)propyl] 5H dibenzo[a,d]cyclohepten 11 ol (MK-940). Convenient laboratory synthesis of 7a was provided by lithiation of 2 bromobenzhydryl methyl ether, followed by addition of 1 methyl 4 piperidone and acid catalyzed cyclization. N Dealkylation by standard methods afforded 9a. Synthesis of analogues was stimulated by discovery of marked inhibition of tetrabenazine induced ptosis for lead compounds 7a and 9a. Optimal antitetrabenazine activity is associated with the 3 phenylspiro[isobenzofuran 1(3H),4' piperidine] moiety where nitrogen is basic. Modification of this moiety by introduction of large nitrogen substituents or a C-3 substituent > H significantly reduced antitetrabenazine activity. A series of analogue with aromatic substituents was investigated; however, few of these compounds were significantly more active than 7a and 9a. Compound 9a was selected for additional studies.
