131292-31-4Relevant articles and documents
Transition-Metal-Free Synthesis of Borylated Thiophenes via Formal Thioboration
Bel Abed, Hassen,Blum, Suzanne A.
supporting information, p. 6673 - 6677 (2018/10/24)
A simple, regiocontrolled, and transition-metal-free approach to access exclusively 3-borylated thiophene derivatives is reported. The commercially available B-chlorocatecholborane reagent (ClBcat) acts as a carbophilic Lewis acid to activate the alkyne i
Cyclobutene vs 1,3-Diene Formation in the Gold-Catalyzed Reaction of Alkynes with Alkenes: The Complete Mechanistic Picture
De Orbe, M. Elena,Amenós, Laura,Kirillova, Mariia S.,Wang, Yahui,López-Carrillo, Verónica,Maseras, Feliu,Echavarren, Antonio M.
supporting information, p. 10302 - 10311 (2017/08/09)
The intermolecular gold(I)-catalyzed reaction between arylalkynes and alkenes leads to cyclobutenes by a [2 + 2] cycloaddition, which takes place stepwise, first by formation of cyclopropyl gold(I) carbenes, followed by a ring expansion. However, 1,3-butadienes are also formed in the case of ortho-substituted arylalkynes by a metathesis-type process. The corresponding reaction of alkenes with aryl-1,3-butadiynes, ethynylogous to arylalkynes, leads exclusively to cyclobutenes. A comprehensive mechanism for the gold(I)-catalyzed reaction of alkynes with alkenes is proposed on the basis of density functional theory calculations, which shows that the two pathways leading to cyclobutenes or dienes are very close in energy. The key intermediates are cyclopropyl gold(I) carbenes, which have been independently generated by retro-Buchner reaction from stereodefined 1a,7b-dihydro-1H-cyclopropa[a]naphthalenes.
Highly enantioselective copper(i)-catalyzed conjugate addition of 1,3-diynes to α,β-unsaturated trifluoromethyl ketones
Sanz-Marco, Amparo,Blay, Gonzalo,Mu?oz, M. Carmen,Pedro, José R.
supporting information, p. 8958 - 8961 (2015/05/27)
The conjugate diynylation of α,β-unsaturated trifluoromethyl ketones is carried out in the presence of a low catalytic load (2.5 mol%) of a copper(i)-MeOBIPHEP complex, triethylamine and a terminal 1,3-diyne. Pre-metalation of the terminal 1,3-diyne with stoichiometric or higher amounts of dialkylzinc reagent is not required. The corresponding internal diynes bearing a propargylic stereogenic center are obtained with good yields and excellent enantioselectivities. This journal is
Synthesis of indenothiophenone derivatives by cycloaromatization of non-conjugated thienyl tetraynes
Kawano, Tomikazu,Inai, Hiroki,Miyawaki, Kazuhiro,Ueda, Ikuo
, p. 1233 - 1236 (2007/10/03)
Non-conjugated thienyl tetrayne derivatives 1-3 are prepared as novel building block for the construction of indenothiophenone derivatives. Oxidation of 1-3, followed by cycloaromatization of the corresponding ketone derivatives 13-15 proceeds smoothly to afford indenothiophenone derivatives 16-21 in good yields.
Flash Vacuum Pyrolysis of Stabilised Phosphorous Ylides. Part 4. Stepwise Construction of Terminal 1,3-Diynes, Conjugated Diacetylenic Esters and a Triacetylenic Ester
Aitken, R. Alan,Seth, Shirley
, p. 2461 - 2466 (2007/10/02)
Thirteen examples of stabilised alkynol ylides 6 have been prepared and are found, upon flash vacuum pyrolysis (FVP) at 500 deg C, to undergo extrusion of Ph3PO to give the diacetylenic esters 7 in moderate yield.At 750 deg C the same ylides afforded terminal 1,3-diynes 8 although often in poor yield.For R = 2-MeSC6H4 both 7 and 8 undergo secondary loss of Me* and cyclisation to give 2-alkynylbenzothiophene derivatives 9 and 10 in low yield.The first example of an alkadiynol ylide 11 has been prepared and is converted by FVP at 500 deg C into the triacetylenic ester 12.
