1071853-94-5Relevant articles and documents
Catalytic Enantioselective Nazarov Cyclization
Jolit, Anais,Dickinson, Cody F.,Kitamura, Kei,Walleser, Patrick M.,Yap, Glenn P. A.,Tius, Marcus A.
, p. 6067 - 6076 (2017/11/14)
A detailed account of an asymmetric Nazarov cyclization that leads to α-hydroxycyclopentenones bearing either vicinal, all-carbon quaternary centers, or vicinal quaternary and tertiary centers is given. The all-aliphatic examples represent the greatest challenge, as the dienone starting materials are not activated toward cyclization by an aryl group. The rational design and optimization of the substrates in parallel with optimization of the chiral Br?nsted acid catalyst is also described, as well as a series of diastereoselective transformations of a fully substituted cyclopentenone product.
N -Triflylphosphorimidoyl Trichloride: A Versatile Reagent for the Synthesis of Strong Chiral Bronsted Acids
Lee, Sunggi,Kaib, Philip S. J.,List, Benjamin
supporting information, p. 1478 - 1480 (2017/07/22)
A series of strong Bronsted acids has been synthesized in high yields using N -triflylphosphorimidoyl trichloride as reagent. The syntheses proceed efficiently with electron-rich, electron-deficient, and sterically hindered substrates.
Synthesis and structural aspects of N-triflylphosphoramides and their calcium salts'highly acidic and effective Bronsted acids
Rueping, Magnus,Nachtsheim, Boris J.,Koenigs, Rene M.,Ieawsuwan, Winai
scheme or table, p. 13116 - 13126 (2011/02/24)
Recently, 1,1′-bi-2-naphthol (BINOL)-based N-triflylphosphoramides emerged as a new class of potent Bronsted acid catalysts. In this paper we describe the efficient synthesis of various BINOL-based N- triflylphosphoramides and their calcium salts. Furthermore, X-ray crystal structure analysis combined with energy-dispersive X-ray spectroscopy (EDX) measurements confirmed that the synthesised chiral N-triflylphosphoramides are highly acidic metal-free catalysts. Freedom! The synthesis and structure determination of various 1,1′-bi-2-naphthol (BINOL)-based N-triflylphosphoramides and their corresponding calcium salts is presented. A simple acidic treatment of the calcium salts provides the metal-free Bronsted acids (see scheme; Tf=trifluoromethanesulfonyl).