- Catalytic Asymmetric Iterative/Domino Aldehyde Cross-Aldol Reactions for the Rapid and Flexible Synthesis of 1,3-Polyols
-
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.
- Lin, Luqing,Yamamoto, Kumiko,Mitsunuma, Harunobu,Kanzaki, Yamato,Matsunaga, Shigeki,Kanai, Motomu
-
supporting information
p. 15418 - 15421
(2015/12/26)
-
- Perfluoroalkyl halides and derivatives
-
Novel mixtures of perfluoroalkyl halides and derivatives thereof are described. These mixtures contain some compounds with a straight perfluoroalkyl group and some with a branched perfluoroalkyl group. Methods of preparation and use are also described.
- -
-
Page column 14
(2010/01/31)
-
- Iodopentahydroperfluoroalkyl borates
-
2-Iodo-1,1,2,3,3-pentahydroperfluoroalkyl borates, their preparation from perfluoroalkyl iodides and triallyl borate in the presence of a free radical initiator, and preparation of perfluoroalkylpropylene iodohydrins by hydrolysis of the borates.
- -
-
-
- N-type betaines of 2-hydroxy-1,1,2,3,3-pentahydroperfluoroalkylamines
-
Amphoteric N-type betaines represented by the formula: STR1 wherein: Rf is C4 -C20 perfluoroalkyl; R1 and R2 are methyl or, together with the N atom to which they are bonded, form a piperidino, morpholino, or N-alkyl(c1 -C4)piperazino group; and m is a whole number between 1 and 4 are highly effective in reducing the surface tension of water and of aqueous solutions of inorganic electrolytes, and can be used in environments where non-amphoteric surfactants would fail, e.g. highly acidic oil well applications.
- -
-
-