Concise synthesis of α-substituted 2-benzofuranmethamines and other 2-substituted benzofurans via α-substituted 2-benzofuranmethyl carbocation intermediates
dc.contributor.author | Wongsa, Nikhom | |
dc.contributor.author | Sommart, Ubonta | |
dc.contributor.author | Ritthiwigrom, Thunwadee | |
dc.contributor.author | Yazici, Arife | |
dc.contributor.author | Kanokmedhakul, Somdej | |
dc.contributor.author | Kanokmedhakul, Kwanjai | |
dc.contributor.author | Willis, Anthony | |
dc.contributor.author | Pyne, Stephen G | |
dc.date.accessioned | 2015-12-13T22:16:16Z | |
dc.date.issued | 2013 | |
dc.date.updated | 2016-02-24T08:57:42Z | |
dc.description.abstract | Propargyl amines 4, where R3 is aryl, undergo 5-exo-dig cyclization reactions under relatively mild conditions (AgNO3, DMF, 60 C, 1 h) to give 3-amino-2,3-dihydro-2-arylmethylidenebenzofurans 5 (R 3 = aryl). In contrast, substrates where R3 is alkyl undergo competing 6-endo-dig and 5-exo-dig cyclization processes. The hydroxymethyl substrate 4 (R3 = CH2OH), however, was smoothly converted to its corresponding 5-exo-dig cyclization product 5, likely due to the assistance of the primary hydroxyl group in the 5-exo-dig cyclization process by silver cation coordination. Under more enforcing conditions (AgNO3, DMF, 100 C, 18 h), the initially formed products 5 undergo a 1,3-allylic rearrangement to their corresponding 2-substituted benzofuran derivatives 6. This rearrangement can also be effected by treating 5 with AgNO3 in DMF at 100 C for 18 h or BF3·Et 2O at rt. 2-(3-Butenyl)benzofurans 7 (Nu = allyl) can be prepared by treatment of 5 with BF3·Et2O and allyltributylstannane. Furan and MeOH could also be employed as external nucleophiles in these BF3·Et2O-promoted reactions. | |
dc.identifier.issn | 0022-3263 | |
dc.identifier.uri | http://hdl.handle.net/1885/70777 | |
dc.publisher | American Chemical Society | |
dc.source | Journal of Organic Chemistry | |
dc.subject | Keywords: 1 ,3-allylic rearrangement; Allyltributylstannane; Benzofurans; Carbocations; Concise synthesis; Cyclization products; Cyclization reactions; Hydroxyl groups; Propargyl; Silver cations; Chemical compounds; Methanol; Substrates; Cyclization; 1 (2 benzylide | |
dc.title | Concise synthesis of α-substituted 2-benzofuranmethamines and other 2-substituted benzofurans via α-substituted 2-benzofuranmethyl carbocation intermediates | |
dc.type | Journal article | |
local.bibliographicCitation.issue | 3 | |
local.bibliographicCitation.lastpage | 1148 | |
local.bibliographicCitation.startpage | 1138 | |
local.contributor.affiliation | Wongsa, Nikhom, Khon Kaen University | |
local.contributor.affiliation | Sommart, Ubonta, Prince of Songkla University | |
local.contributor.affiliation | Ritthiwigrom, Thunwadee, University of Wollongong | |
local.contributor.affiliation | Yazici, Arife, University of Wollongong | |
local.contributor.affiliation | Kanokmedhakul, Somdej, Khon Kaen University | |
local.contributor.affiliation | Kanokmedhakul, Kwanjai, Khon Kaen University | |
local.contributor.affiliation | Willis, Anthony, College of Physical and Mathematical Sciences, ANU | |
local.contributor.affiliation | Pyne, Stephen G, University of Wollongong | |
local.contributor.authoremail | u8512028@anu.edu.au | |
local.contributor.authoruid | Willis, Anthony, u8512028 | |
local.description.embargo | 2037-12-31 | |
local.description.notes | Imported from ARIES | |
local.identifier.absfor | 030503 - Organic Chemical Synthesis | |
local.identifier.absseo | 970103 - Expanding Knowledge in the Chemical Sciences | |
local.identifier.ariespublication | f5625xPUB2411 | |
local.identifier.citationvolume | 78 | |
local.identifier.doi | 10.1021/jo302554v | |
local.identifier.scopusID | 2-s2.0-84873325933 | |
local.identifier.thomsonID | 000314558300033 | |
local.identifier.uidSubmittedBy | f5625 | |
local.type.status | Published Version |
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