0000000001309550
AUTHOR
Uğur Kaya
Diastereoselective Synthesis of Spiro[pyrazolone-4,3′-tetrahydrothiophenes] via a Sulfa-Michael/Aldol Domino Reaction
Synthesis : journal of synthetic organic chemistry 48(23), 4091-4098(2016). doi:10.1055/s-0035-1562473
Asymmetric Synthesis of Spiro β-Lactamsviaa Squaramide- Catalyzed Sulfa-Michael Addition/Desymmetrization Protocol
An efficient asymmetric synthesis of spirocyclohexenone β-lactams bearing three contiguous stereocenters has been achieved in moderate to good yields and high stereoselectivities. The protocol involves the combination of a squaramide-catalyzed sulfa-Michael addition under desymmetrization via a dynamic kinetic resolution of racemic 2,5-cyclohexadienones.
Enantioselective synthesis of pyrazolone α-aminonitrile derivatives via an organocatalytic Strecker reaction
A new organocatalytic enantioselective Strecker reaction of pyrazolone-derived ketimine electrophiles has been developed. Using pseudo-enantiomeric squaramide catalysts the nucleophilic 1,2-addition of trimethylsilyl cyanide to the ketimines efficiently provides a direct entry to both enantiomers of pyrazolone α- aminonitrile derivatives at will in good yields and high enantioselectivities for a wide variety of substrates. peerReviewed
Squaramide-Catalyzed Asymmetric aza-Friedel-Crafts/N,O-Acetalization Domino Reactions Between 2-Naphthols and Pyrazolinone Ketimines
N-Boc ketimines derived from pyrazolin-5-ones were explored to develop an unprecedented domino aza-Friedel-Crafts/N,O-acetalization reaction with 2-naphthols. The novel method requires a catalyst loading of only 0.5 mol % of a bifunctional squaramide catalyst, is scalable to gram amounts, and provides a new series of furanonaphthopyrazolidinone derivatives bearing two vicinal tetra-substituted stereogenic centers in excellent yields (95-98 %) and stereoselectivity (>99:1 d.r. and 97-98 % ee). A different reactivity was observed in the case of 1-naphthols and other electron-rich phenols, which led to the aza-Friedel-Crafts adducts in 70-98 % yield and 47-98 % ee.
Asymmetric Synthesis of Tetrahydrobenzofurans and Annulated Dihydropyrans via Cooperative One-Pot Organo- and Silver-Catalysis
Synthesis : journal of synthetic organic chemistry 48(19), 3207-3216(2016). doi:10.1055/s-0035-1561468
Enantioselective synthesis of 4H-pyranonaphthoquinones via sequential squaramide and silver catalysis
Chemical communications 52(8), 1669-1672(2016). doi:10.1039/C5CC09592A
Asymmetric Synthesis of Amino-Bis-Pyrazolone Derivatives via an Organocatalytic Mannich Reaction.
A new series of N-Boc ketimines derived from pyrazolin-5-ones have been used as electrophiles in asymmetric Mannich reactions with pyrazolones. The amino-bis-pyrazolone products are obtained in excellent yields and stereoselectivities by employing a very low loading of 1 mol % of a bifunctional squaramide organocatalyst. Depending on the substitution at position 4 of the pyrazolones, the new protocol allows for the generation of one or two tetrasubstituted stereocenters, including a one-pot version combing the Mannich reaction with a base-mediated halogenation. peerReviewed
CCDC 1542055: Experimental Crystal Structure Determination
Related Article: Suruchi Mahajan, Pankaj Chauhan, Uğur Kaya, Kristina Deckers, Kari Rissanen, Dieter Enders|2017|Chem.Commun.|53|6633|doi:10.1039/C7CC02874A
CCDC 1474771: Experimental Crystal Structure Determination
Related Article: Uğur Kaya, Pankaj Chauhan, Kristina Deckers, Rakesh Puttreddy, Kari Rissanen, Gerhard Raabe, Dieter Enders|2016|Synthesis|48|3207|doi:10.1055/s-0035-1561468
CCDC 1474975: Experimental Crystal Structure Determination
Related Article: Uğur Kaya, Pankaj Chauhan, Kristina Deckers, Rakesh Puttreddy, Kari Rissanen, Gerhard Raabe, Dieter Enders|2016|Synthesis|48|3207|doi:10.1055/s-0035-1561468
CCDC 1537523: Experimental Crystal Structure Determination
Related Article: Pankaj Chauhan, Suruchi Mahajan, Uğur Kaya, Anssi Peuronen, Kari Rissanen, and Dieter Enders|2017|J.Org.Chem.|82|7050|doi:10.1021/acs.joc.7b01113
CCDC 1537522: Experimental Crystal Structure Determination
Related Article: Pankaj Chauhan, Suruchi Mahajan, Uğur Kaya, Anssi Peuronen, Kari Rissanen, and Dieter Enders|2017|J.Org.Chem.|82|7050|doi:10.1021/acs.joc.7b01113
CCDC 1476009: Experimental Crystal Structure Determination
Related Article: Pankaj Chauhan, Suruchi Mahajan, Uğur Kaya, Arto Valkonen, Kari Rissanen and Dieter Enders|2016|Adv.Synth.Catal.|358|3173|doi:10.1002/adsc.201600554
CCDC 1437688: Experimental Crystal Structure Determination
Related Article: Uğur Kaya, Pankaj Chauhan, Daniel Hack, Kristina Deckers, Rakesh Puttreddy, Kari Rissanen, Dieter Enders|2016|Chem.Commun.|52|1669|doi:10.1039/C5CC09592A
CCDC 1572983: Experimental Crystal Structure Determination
Related Article: Uğur Kaya, Pankaj Chauhan, Suruchi Mahajan, Kristina Deckers, Arto Valkonen, Kari Rissanen, Dieter Enders|2017|Angew.Chem.,Int.Ed.|56|15358|doi:10.1002/anie.201709224