65564-92-3Relevant academic research and scientific papers
Recoverable polystyrene-supported palladium catalyst for construction of all-carbon quaternary stereocenters via asymmetric 1,4-addition of arylboronic acids to cyclic enones
Bartá?ek, Jan,Váňa, Ji?í,Drabina, Pavel,Svoboda, Jan,Kocúrik, Martin,Sedlák, Milo?
, (2020/05/16)
The development of recoverable catalysts based on the combination of synthetically demanding ligands with transition metals attracts a lot of attention, especially from the environmental point of view. In this paper, we describe the preparation of a recoverable polystyrene supported chiral palladium catalyst based on PyOx ligand suitable for asymmetric 1,4-addition of arylboronic acids to cyclic 3-substituted five- and six-membered enones. In the reaction, all?carbon quaternary stereocenters are formed with a high level of enantioselectivity (up to 91% ee) and conversion (up to 99%). The catalyst was used in 6 cycles with no loss of enantioselectivity and only a small decrease in conversion. A solution of the problems associated with the transition from homogeneous to heterogeneous catalytic systems is discussed.
Catalytic asymmetric total syntheses of (+)-α-cuparenone, (+)-cuparene and (+)-herbertene
Shaw, Kundan,Niyogi, Sovan,Nandi, Rhituparna,Bisai, Vishnumaya
supporting information, (2020/07/15)
A general catalytic asymmetric route to either enantiomers of sesquiterpenes, cuparenes (1–2) and herbertenes (8–9) is disclosed from commercially available 3-methyl cyclopenten-2-one. Following a catalytic enantioselective addition of arylboronic acids to enone 15, compounds 14a-b with all carbon quaternary stereocenters are synthesized in up to 90percent ee in the presence of Pd(II)-PyOx (pyridine oxazoline). Compounds 14a-b are used as precursors for the asymmetric total syntheses of (+)-cuparene (1a) (35percent overall yield in 3 steps), α-(+)-cuparenone (1b) (56percent overall yield in 2 steps), and (+)-herbertene (8a) (34percent overall yield in 3 steps).
Stepwise approach for sterically hindered Csp3-Csp3 bond formation by dehydrogenative: O -alkylation and Lewis acid-catalyzed [1,3]-rearrangement towards the arylalkylcyclopentane skeleton of sesquiterpenes
Fujitani, Ban,Hanaya, Kengo,Sugai, Takeshi,Higashibayashi, Shuhei
supporting information, p. 3621 - 3624 (2020/04/07)
A stepwise dehydrogenative cross-coupling method was developed for the formation of sterically hindered Csp3-Csp3 bonds. Intramolecular dehydrogenative O-alkylation of a β-ketoester by 2,3-dichloro-5,6-dicyano-p-benzoquinone to form an oxolane followed by Lewis acid-catalyzed [1,3]-rearrangement furnished the sesquiterpene arylmethylcyclopentane skeleton. The formal syntheses of herbertane-type β-herbertenol, cuparane-type enokipodins A and B were also achieved.
Pyridine-Hydrazone Ligands in Asymmetric Palladium-Catalyzed 1,4- and 1,6-Additions of Arylboronic Acids to Cyclic (Di)enones
de Gracia Retamosa, María,álvarez-Casao, Yolanda,Matador, Esteban,Gómez, ángela,Monge, David,Fernández, Rosario,Lassaletta, José M.
, p. 176 - 184 (2018/12/11)
Catalysts generated by combinations of Pd(TFA)2 and enantiomerically pure pyridine-hydrazone ligands have been applied to the 1,4-addition of arylboronic acids to β-substituted cyclic enones, building all-carbon quaternary stereocenters in high
Efficient formation of benzylic quaternary centers via palladium catalysis
Gottumukkala, Aditya L.,Suljagic, Jasmin,Matcha, Kiran,De Vries, Johannes G.,Minnaard, Adriaan J.
, p. 1636 - 1639 (2013/10/21)
Four's a crowd: An efficient protocol for the formation of benzylic quaternary centers via arylation of enones using a catalyst made from Pd(O 2CCF3)2 and 2,2′-bipyridine is developed. For cyclic substrates, catalyst loadi
A chiral pool based approach to antipodes of α-cuparenone
Chavan, Subhash P.,Lasonkar, Pradeep B.
, p. 1496 - 1500,5 (2012/12/12)
A synthetic route to both antipodes of α-cuparenone was achieved from the readily available chiral pool starting material l-malic acid and involved cyclopentannulation as the key step.
A chiral pool based approach to antipodes of α-cuparenone
Chavan, Subhash P.,Lasonkar, Pradeep B.
, p. 1496 - 1500 (2013/01/15)
A synthetic route to both antipodes of α-cuparenone was achieved from the readily available chiral pool starting material l-malic acid and involved cyclopentannulation as the key step.
Palladium-catalyzed asymmetric quaternary stereocenter formation
Gottumukkala, Aditya L.,Matcha, Kiran,Lutz, Martin,De Vries, Johannes G.,Minnaard, Adriaan J.
experimental part, p. 6907 - 6914 (2012/07/01)
An efficient palladium catalyst is presented for the formation of benzylic quaternary stereocenters by conjugate addition of arylboronic acids to a variety of β,β-disubstituted carbocyclic, heterocyclic, and acyclic enones. The catalyst is readily prepared from PdCl2, PhBOX, and AgSbF 6, and provides products in up to 99 % enantiomeric excess, with good yields. Based on this strategy, (-)-α-cuparenone has been prepared in only two steps. Copyright
Cyclopropyl methyl bromide-mediated gem-diallylation: Total synthesis of (±)-α-cuparenone
Shivakumar,Salunke, Ganesh B.,Kumar, Suneel
experimental part, p. 1952 - 1957 (2011/06/26)
The total synthesis of (±)-α-cuparenone, an aromatic sesquiterpene, has been described using the radical mediated gem-diallylation of substituted cyclopropyl methylbromide followed by ring-closing metathesis approach.
An efficient and practical total synthesis of (±)-α-cuparenone
Chavan, Subhash P.,Dhawane, Abasaheb N.,Kalkote, Uttam R.
, p. 3827 - 3830 (2008/09/17)
A one-pot cyclopentannulation approach as the key step for the total synthesis of (±)-α-cuparenone is described. Georg Thieme Verlag Stuttgart.
