Nonenzymatic Acylative Kinetic Resolution of Baylis−Hillman Adducts
摘要:
The first efficient nonenzymatic acylative kinetic resolution of Baylis-Hillman adducts is reported. Chiral pyridine catalyst 1a and an optimized analogue 1e are capable of promoting the synthetically useful enantioselective acylation (the efficiency of which is outstanding for sp(2)-sp(2) carbinol substrates, s = 3.5-13.1, ee up to 97%) of Baylis-Hillman adducts derived from recalcitrant precursors which are currently difficult to synthesize utilizing benchmark asymmetric Baylis-Hillman reaction catalyst technology. A novel one-pot synthesis-kinetic resolution process involving a DBU-catalyzed Baylis-Hillman reaction and subsequent 1e/DBU-mediated enantioselective acylation has also been developed.
This invention aims at providing a catalyst for producing an optically active aldehyde or an optically active ketone, which is an optically active carbonyl compound, by carrying out selective asymmetric hydrogenation of an α,β-unsaturated carbonyl compound, particularly a catalyst which is insoluble in a reaction mixture for obtaining optically active citronellal which is useful as a flavor or fragrance, by carrying out selective asymmetric hydrogenation of citral, geranial or neral; and a method for producing a corresponding optically active carbonyl compound. The invention relates to a catalyst for asymmetric hydrogenation of an α,β-unsaturated carbonyl compound, which comprises a powder of at least one metal selected from metals belonging to Group 8 to Group 10 of the Periodic Table, or a metal-supported substance in which at least one metal selected from metals belonging to Group 8 to Group 10 of the Periodic Table is supported on a support, an optically active cyclic nitrogen-containing compound and an acid.
A series of chiral pyridoxals 8 and 9 have been developed from commercially available pyridoxine and (S)-alpha,alpha-diarylprolinols. The pyridoxals exhibited good catalytic activity in an asymmetric transamination of alpha-keto acids with 2,2-diphenylglycine (7f) as the amine source to give various alpha-amino acids in 29-85% yields with 53-80% ee's. The current asymmetric transamination has successfully mimicked a complete biological transamination process characterized by two half-transaminations, a small chiral pyridoxal molecule acting as the catalyst, and enantioselective control.
US8217204B2
申请人:——
公开号:US8217204B2
公开(公告)日:2012-07-10
Nonenzymatic Acylative Kinetic Resolution of Baylis−Hillman Adducts
作者:Ciarán Ó Dálaigh、Stephen J. Connon
DOI:10.1021/jo071223b
日期:2007.8.31
The first efficient nonenzymatic acylative kinetic resolution of Baylis-Hillman adducts is reported. Chiral pyridine catalyst 1a and an optimized analogue 1e are capable of promoting the synthetically useful enantioselective acylation (the efficiency of which is outstanding for sp(2)-sp(2) carbinol substrates, s = 3.5-13.1, ee up to 97%) of Baylis-Hillman adducts derived from recalcitrant precursors which are currently difficult to synthesize utilizing benchmark asymmetric Baylis-Hillman reaction catalyst technology. A novel one-pot synthesis-kinetic resolution process involving a DBU-catalyzed Baylis-Hillman reaction and subsequent 1e/DBU-mediated enantioselective acylation has also been developed.
10.1021/jacs.4c01286
作者:Pereira, Oliver、Ruth, Marcel、Gerbig, Dennis、Wende, Raffael C.、Schreiner, Peter R.
DOI:10.1021/jacs.4c01286
日期:——
a particularly difficult reaction, namely, the Corey–Bakshi–Shibata (CBS) reduction of butanone, which constitutes the classic and prototypical challenge of being able to differentiate a methyl from an ethylgroup. As there are no known strategies on how to address this challenge, we leveraged the power of machine learning by constructing a realistic (for a typical laboratory) small, albeit high-quality