224629-50-9Relevant academic research and scientific papers
Enantioselective Construction of Spiro Quaternary Carbon Stereocenters via Pd-Catalyzed Intramolecular α-Arylation
Wu, Ting,Kang, Xuehua,Bai, Heng,Xiong, Wenrui,Xu, Guangqing,Tang, Wenjun,Tang, Wenjun
supporting information, p. 4602 - 4607 (2020/06/29)
We herein report the development of a sterically hindered and electron-rich P-chiral monophosphorus biaryl ligand that has enabled a general and efficient enantioselective intramolecular α-arylation, providing access to a wide series of [4.4], [4.5], and [4.6]-spirocycles with chiral benzylic quaternary carbons in high yields with good to excellent enantioselectivities. A pronounced water effect on enantioselectivity is observed.
Mechanistic studies of copper(I)-catalyzed 1,3-halogen migration
Van Hoveln, Ryan,Hudson, Brandi M.,Wedler, Henry B.,Bates, Desiree M.,Le Gros, Gabriel,Tantillo, Dean J.,Schomaker, Jennifer M.
supporting information, p. 5346 - 5354 (2015/05/13)
An ongoing challenge in modern catalysis is to identify and understand new modes of reactivity promoted by earth-abundant and inexpensive first-row transition metals. Herein, we report a mechanistic study of an unusual copper(I)-catalyzed 1,3-migration of 2-bromostyrenes that reincorporates the bromine activating group into the final product with concomitant borylation of the aryl halide bond. A combination of experimental and computational studies indicated this reaction does not involve any oxidation state changes at copper; rather, migration occurs through a series of formal sigmatropic shifts. Insight provided from these studies will be used to expand the utility of aryl copper species in synthesis and develop new ligands for enantioselective copper-catalyzed halogenation.
Syntheses of 3,4-benzotropolones by ring-closing metatheses
Arican, Deniz,Brückner, Reinhard
supporting information, p. 2582 - 2585 (2013/07/19)
Ortho-lithiated styrenes or ortho-lithiated benzaldehyde dimethyl acetals were added to 2,2-dimethoxypent-4-enals 7. The resulting alcohols were carried on to the aromatic dienones 10. These were ring-closed by olefin metathesis. Hydrolysis of the dimethyl ketal moiety and enolization provided the 3,4-benzotropolones 5. Overall, this access comprises 4-6 steps and totaled a 22-81% yield.
CN-assisted oxidative cyclization of cyano cinnamates and styrene derivatives: A facile entry to 3-substituted chiral phthalides
Reddy, R.Santhosh,Kiran, I. N. Chaithanya,Sudalai, Arumugam
supporting information; experimental part, p. 3655 - 3661 (2012/05/31)
The asymmetric dihydroxylation (AD) of o-cyano cinnamates and styrene derivatives leads to efficient construction of chiral phthalide frameworks in high optical purities. This unique reaction is characterized by unusual synergism between CN and osmate groups resulting in rate enhancement of the AD process. The method is amply demonstrated by the synthesis and the structural/stereochemical assignment of the natural products.
Oxygenated dihydrophenanthrenes via quinol acetals: A brief synthesis of orchinol
Broering, Teresa J.,Morrow, Gary W.
, p. 1135 - 1142 (2007/10/03)
The dihydrophenanthrene phytoalexin Orchinol was synthesized in 5 steps from commercially available 3,5-dimethoxybenzaldehyde. The approach utilized a new synthon, p-benzoquinone dibenzylmonoacetal, which served as a phenol 3,4-dication equivalent in an a
