40297-86-7Relevant academic research and scientific papers
Concise, stereodivergent and highly stereoselective synthesis of cis-and trans-2-substituted 3-hydroxypiperidines-development of a phosphite-driven cyclodehydration
Huy, Peter H.,Westphal, Julia C.,Koskinen, Ari M.P.
supporting information, p. 369 - 383 (2014/03/21)
A concise (5 to 6 steps), stereodivergent, highly diastereoselective (dr up to >19:1 for both stereoisomers) and scalable synthesis (up to 14 g) of cis- and trans-2-substituted 3-piperidinols, a core motif in numerous bioactive compounds, is presented. This sequence allowed an efficient synthesis of the NK-1 inhibitor L-733,060 in 8 steps. Additionally, a cyclodehydration-realizing simple triethylphosphite as a substitute for triphenylphosphine is developed. Here the stoichiometric oxidized P(V)-byproduct (triethylphosphate) is easily removed during the work up through saponification overcoming separation difficulties usually associated to triphenylphosphine oxide.
Efficient, stereodivergent access to 3-piperidinols by traceless P(OEt)3 cyclodehydration
Huy, Peter H.,Koskinen, Ari M. P.
supporting information, p. 5178 - 5181 (2013/11/06)
A stereodivergent and highly diastereoselective (dr up to >19:1 for both isomers), step economic (5-6 steps), and scalable synthesis (up to 14 g) of cis- and trans-2-substituted 3-piperidinols, the core motif of numerous bioactive compounds, providing efficient access to the NK-1 inhibitor L-733,060 is presented. Additionally, a "traceless" (referring to the simplified byproduct separation) cyclodehydration realizing simple P(OEt)3 as a substitute for PPh3 is developed.
A facile synthesis of 1,5-disubstituted-2-aminoimidazoles: Antibiotic activity of a first generation library
Harris, Tyler L.,Worthington, Roberta J.,Melander, Christian
supporting information; experimental part, p. 4516 - 4519 (2011/09/12)
An efficient synthetic route to 1,5-disubstituted 2-aminoimidazoles from readily available amino acids and aldehydes has been developed. A library of simple analogues was synthesized and several compounds were shown to exhibit notable antibiotic activity
Syntheses of optically active α-amino nitrites by asymmetric transformation of the second kind using a principle of O. Dimroth
Hassan, Nasser A.,Bayer, Erwin,Jochims, Johannes C.
, p. 3747 - 3757 (2007/10/03)
A mixture of solids As and Bs in equilibrium with the dissolved compounds A1 and B1 is transformed completely into one pure solid, say Bs, if the dissolved compounds A1?B1 are equilibrating in solution. This is applied to transform 1:1 mixtures of solid diastereomeric amygdalates (2-hydroxy-2-phenylacetates; mandelates) (R,R)-3 + (S,R)-3 prepared from racemic α-amino nitriles (R,S)-1 with (R)-mandelic acid 2 into stereochemically pure single diastereomers (R,R)-3, or (S,R)-3 (de > 97%) ('asymmetric transformation of the second kind by application of Dimroth's principle'). Decomposition of the amygdalates (R,R)-3, or (S,R)-3, with aqueous base affords the enantiomerically pure α-amino nitriles (A)-1, or (S)-1 (ten examples). The chiral auxiliary (R)-mandelic acid is recovered almost quantitatively. The optically active α-amino nitriles are hydrolyzed to amides 6, and further to α-N-alkylamino acids 7. N-Benzylamino acids 7 are hydrogenated to α-amino acids 8. Some of the optically active α-amino nitriles 1 are reduced to optically active 1,2-diamines 9. In most cases, absolute configurations could be assigned by comparison of the specific rotations observed with those of authentic compounds.
2-Thiazolyl α-amino ketones: A new class of reactive intermediates for the stereocontrolled synthesis of unusual amino acids
Dondoni,Perrone
, p. 1162 - 1176 (2007/10/02)
The thiazole-based one carbon homologation of four α-amino acids (L-phenylalanine, L-leucine, L-threonine, and L-serine) to the corresponding α-hydroxy β-amino aldehydes and acids in both configurations at C(α), is described. The methodology involves the following key operations: (i) the conversion of an α-amino ester to a 2-thiazolyl α-amino ketone; (ii) the stereocontrolled reduction of a ketone carbonyl to either syn or anti α,β-amino alcohols; (iii) the aldehyde release from the thiazole ring; (iv) the oxidation of the aldehyde to a carboxylic acid. The methodology was only partially applied to L-phenylglycine because of some limitations in operation (i).
