119405-97-9Relevant articles and documents
Gold-catalyzed [4+3] and [4+4]-annulation reactions of: T -butyl propiolate derivatives with epoxides and oxetanes for the construction of 1,4-dioxepane and 1,5-dioxocane cores
Sahani, Rajkumar Lalji,Liu, Rai-Shung
, p. 7482 - 7485 (2016)
Gold-catalyzed [4+n]-annulations (n = 3, 4) of tert-butyl propiolate derivatives with epoxides or oxetanes proceed smoothly to yield seven- or eight-membered oxacyclic products efficiently. In the context of the [4+3]-annulations, product analysis reveals a retention of stereochemistry upon the intramolecular SN2 attack of an epoxide. We also report the [4+5]-annulation between one tert-butyl propiolate and γ-lactol, to manifest the utility toward medium-sized rings.
Regio- and diastereoselective construction of spirocyclopenteneoxindoles through phosphine-catalyzed [3 + 2] annulation of methyleneindolinone with alkynoate derivatives
Zhang, Jiayong,Cheng, Cheng,Wang, Dian,Miao, Zhiwei
, p. 10121 - 10128 (2017)
A phosphine-catalyzed [3 + 2] annulation of isatin-derived α,β-unsaturated ketones with alkynoates for the synthesis of cyclopentene spiro-oxindole skeletons has been developed. This reaction afforded the desired products in high to excellent yields (up to 99%) with high regioselectivity and moderate to high diastereoselectivities (up to 20:1). This strategy allows facile diastereoselective preparation of biologically important spiro-(cyclopentene) oxindoles containing three contiguous stereocenters, including the quaternary stereogenic center joining the two rings.
Removal of triphenylphosphine oxide by precipitation with zinc chloride in polar solvents
Batesky, Donald C.,Goldfogel, Matthew J.,Weix, Daniel J.
, p. 9931 - 9936 (2017)
While the use of triphenylphosphine as a reductant is common in organic synthesis, the resulting triphenylphosphine oxide (TPPO) waste can be difficult to separate from the reaction product. While a number of strategies to precipitate TPPO are available, none have been reported to work in more polar solvents. We report here that mixing ZnCl2 with TPPO precipitates a TPPO?Zn complex in high yield in several common polar organic solvents. The solvent compatibility of this procedure and the reliability of the precipitation in the presence of polar functional groups were examined to show the utility and limitations of this method.
Nickel-Catalyzed, Regio- and Enantioselective Benzylic Alkenylation of Olefins with Alkenyl Bromide
Liu, Jiandong,Gong, Hegui,Zhu, Shaolin
supporting information, p. 4060 - 4064 (2020/12/25)
A NiH-catalyzed migratory hydroalkenylation reaction of olefins with alkenyl bromides has been developed, affording benzylic alkenylation products with high yields and excellent chemoselectivity. The mild conditions of the reaction preclude olefinic products from undergoing further isomerization or subsequent alkenylation. Catalytic enantioselective hydroalkenylation of styrenes was achieved by using a chiral bisoxazoline ligand.
Synthesis of 1,3-Diynes via Cadiot-Chodkiewicz Coupling of Volatile, in Situ Generated Bromoalkynes
Knutson, Phil C.,Fredericks, Haleigh E.,Ferreira, Eric M.
supporting information, p. 6845 - 6849 (2018/10/25)
A convenient Cadiot-Chodkiewicz protocol that facilitates the use of low molecular weight alkyne coupling partners is described. The method entails an in situ elimination from a dibromoolefin precursor and immediate subjection to copper-catalyzed conditions, circumventing the hazards of volatile brominated alkynes. The scope of this method is described, and the internal 1,3-diyne products are preliminarily evaluated in ruthenium-catalyzed azide-alkyne cycloadditions.
