title: Catalytic Asymmetric Iterative/Domino Aldehyde Cross-Aldol Reactions for the Rapid and Flexible Synthesis of 1,3-Polyols.
abstract: We report here catalytic asymmetric iterative and domino cross-aldol reactions between aldehydes, endowed with a high level of robustness, flexibility, and generality. A Cu(I)-DTBM-SEGPHOS complex catalyzes an asymmetric cross-aldol reaction between acceptor aldehydes and boron enolates derived from donor aldehydes, which are generated through Ir-catalyzed isomerization of allyloxyboronates. The unit process can be repeated using the aldol products in turn as acceptor substrates for the subsequent asymmetric aldol reaction. The donor aldehydes and stereoselectivity can be flexibly switched in a stepwise manner for the double-aldol reaction. Furthermore, asymmetric triple- and quadruple-aldol reactions are possible in one-pot using the appropriate amounts of donors and amine additives, rapidly elongating the carbon skeleton with controlling up to eight stereocenters. The method should be useful for straightforward synthesis of enantiomerically and diastereomerically enriched 1,3-polyols.
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.|ERATO, Japan Science and Technology Agency , Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Luqing
authors.initials: L
authors.lastname: Lin
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Harunobu
authors.initials: H
authors.lastname: Mitsunuma
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Yamato
authors.initials: Y
authors.lastname: Kanzaki
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.|ACT-C, Japan Science and Technology Agency , Tokyo 113-0033, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Matsunaga
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.|ERATO, Japan Science and Technology Agency , Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Motomu
authors.initials: M
authors.lastname: Kanai