Monday, February 17, 2014
Zara M. Seibel and Tristan H. Lambert
Construction of Alkylated Stereocenters
Hirohisa Ohmiya and Masaya Sawamura at Hokkaido University reported (Angew. Chem. Int. Ed. 2013, 52, 5350. ) the copper-catalyzed, γ-selective allylation of terminal alkyne 1 to produce the chiral skipped enyne 3 with high ee. A method to synthesize asymmetric skipped diene 6 via copper-catalyzed allylic allylation of diene 4 was developed (Chem. Commun. 2013, 49, 3309. ) by Ben L. Feringa at the University of Groningen. Prof. Feringa also disclosed (J. Am. Chem. Soc. 2013, 135, 2140. ) the regioselective and enantioselective allyl-allyl coupling of bromide 7 with allyl Grignard under copper-catalysis in the presence of phosphoramidite 8. James P. Morken of Boston College reported (Org. Lett. 2013, 15, 1432. ) the cross-coupling of allylboronate 11 with a mixture of alkenes 10a,b under palladium catalysis to produce diene 13 with high ee.
Jian Liao at the the Chengdu Institute of Biology Chinese Academy of Sciences and the University of Chinese Academy of Sciences reported (Angew. Chem. Int. Ed. 2013, 52, 4207. ) the palladium-catalyzed allylic alkylation of indole using the chiral bis(sulfoxide) phosphine ligand 15. Yi-Xia Jia at the Zhejiang University of Technology reported (J. Am. Chem. Soc. 2013, 135, 2983. ) the enantioselective alkylation of indole to produce the trifluoromethyl adduct 19 using nickel catalysis in the presence of bisoxazoline ligand 18.
Sarah E. Reisman at the California Institute of Technology disclosed (J. Am. Chem. Soc. 2013, 135, 7442. ) the reductive cross-coupling of acid chloride 20 and benzyl chloride 21 using a nickel complex with bisoxazoline ligand 22 and manganese(0) as reductant. Ilan Marek at the Technion-Israel Institute of Technology reported (Angew. Chem. Int. Ed. 2013, 52, 5333. ) a method for the construction of all-carbon quaternary stereocenters like the one present in aldehyde 25 using a diastereoselective carbometallation of cyclopropene 24 followed by oxidation and ring-opening. Switching from methyl Grignard and copper iodide to MeCuCNLi reverses the diastereoselectivity of the carbometallation and allows access to the opposite enantiomer.
Matthew S. Sigman at the University of Utah reported (J. Am. Chem. Soc. 2013, 135, 6830. ) the redox-relay oxidative Heck arylation of alkenyl alcohol 27 with boronic acid 26, using a palladium catalyst and pyridine oxazole ligand 28 to produce the γ-substituted aldehyde 29. Karl Anker Jĝrgenson at Aarhus University disclosed (J. Am. Chem. Soc. 2013, 135, 8063. ) the 1,6-Michael addition of alkylidene lactone 30 to dienal 31 using proline-derived catalyst 32 and catalytic Hünig' s base.
Qi-Lin Zhou at Nankai University reported (Angew. Chem. Int. Ed. 2013, 52, 1556. ) the carboxyl-directed asymmetric hydrogenation of alkene 34 using chiral iridium catalyst 35. An asymmetric hydrogenation of enone 37 using an enoate reductase and dihydropyridine 38, a synthetic substitute for natural nicotinamide that preserves the natural activity and selectivity of the reductase, was reported (Org. Lett. 2013, 15, 180. ) by Frank Hollmann at the Delft University of Technology.
Andrew D. Smith at the University of Saint Andrews disclosed (Chem. Sci. 2013, 4, 2193. ) the enantioselective Michael addition of diketone 42 to anhydride 41 under catalysis by isothiourea 43 and PS-BEMP, a polymer supported phosphorine base. Finally, Yixin Lu at the National University of Singapore reported (Angew. Chem. Int. Ed. 2013, 52, 943. ) the Michael addition of oxindole 45 to methyl vinyl ketone with the phosphine catalysts 46, which represents the first example of a chiral phosphine promoting an asymmetric Michael reaction.
Z. M. Seibel, T. H. Lambert, Org. Chem. Highlights 2014, February 17.