Keiji Maruoka of Kyoto University (J. Am. Chem. Soc. 2009, 131, 3450) and Yujiro Hayashi of the Tokyo University of Science (Chem. Commun. 2009, 3083) independently developed organocatalysts for the enantioselective α-benzoylation of aliphatic aldehydes such as 1. The product 3 can be readily carried on to, inter alia, either enantiomer of the epoxide. Chengjian Zhu of Nanjing University designed (Adv. Synth. Cat. 2009, 351, 920) a chiral salen complex that mediated the enantioselective opening of both cyclohexene oxide (4) and cyclopentene oxide. This reagent combination might also engage just one of the two enantiomers of a racemic cycloalkene epoxide. Lin Pu of the University of Virginia established (Organic Lett. 2009, 11, 2441) a BINOL catalyst for the addition of ethyl propiolate 7 to an aliphatic aldehyde 6 to give the alcohol 8 in high ee. In a complementary approach, Do Hyun Ryu of Sungkyunkwan University found (Angew. Chem. Int. Ed. 2009, 48, 4398) that an oxazaborolidinium salt catalyzed the addition of 7 to 9 to give 10 with high ee and high geometric control. Jianliang Xiao of the University of Liverpool devised (J. Am. Chem. Soc. 2009, 131, 6967) an Ir catalyst for the enantioselective reductive amination of a ketone 11 to the amine 13 . Karl B. Hansen, Yi Hsiao. and Feng Xu, then all at Merck/Rahway, showed (J. Am. Chem. Soc. 2009, 131, 8798) that it was possible to hydrogenate a vinylogous primary amide 14 to the amine 15 with high enantiocontrol. Takashi Ooi of Nagoya University designed (J. Am. Chem. Soc. 2009, 131, 7242) a chiral P-spiro tetraaminophosphonium catalyst that mediated the enantioselective addition of anilines to nitroalkenes such as 16. The product 18 could be carried on to the 1,2-diamine, or to the α-amino acid. Masahiro Terada of Tohoku University devised (Angew. Chem. Int. Ed. 2009, 48, 2553) a BINOL-derived phosphonic acid to catalyze the enantioselective 1,2-addition of the enamide 20 to the imine derived from 19. Yixin Lu of the National University of Singapore found (Organic Lett. 2009, 11, 1721) that a cinchona alkaloid-derived thiourea effectively catalyzed the enantioselective conjugate addition of nitroalkanes such as 22 to the acceptor 23.
Sequential catalysis: exploiting a single rhodium(i) catalyst to promote an alkyne hydroacylation–aryl boronic acid conjugate addition sequence
