D- and L- &agr;-amino acids and D- and L-&agr;-amino aldehydes are synthesized from olefin substrates in two steps. The first step is a catalyzed asymmetric aminohydroxylation addition reaction to the olefin substrate. The addition reaction is catalyzed by osmium and is co-catalyzed by chiral ligands. The chiral ligands, in addition to being co-catalysts with the osmium, also serve to direct the addition reaction regioselectively and enantioselectively, divalent ligands are preferred over monovalent ligands because of their enhanced regio-and enantio-selectivity. As an oxidant nitrogen source for the addition reaction, either a carbamate or sulfonamide may be employed. If carbamate is employed as an oxidant nitrogen source, the resultant &bgr;-hydoxycarbamate is deprotected to yield the corresponding &bgr;-hydroxyamine. If sulfonamide is employed as an oxidant nitrogen source, the resultant &bgr;-hydroxysulfonamide is deprotected to yield the corresponding &bgr;-hydroxyamine. The resultant &bgr;-hydroxyamine is then selectively oxidized in a second synthetic step to produce the desired D- and L- &agr;-amino acid or D- and L-&agr;-amino aldehyde.
D-和L-
α-氨基酸以及D-和L-α-
氨基醛可以从烯烃底物中的两个步骤合成。第一步是催化的不对称
氨羟化加成反应,作用于烯烃底物。加成反应由
铂催化,并由手性
配体共同催化。除了与
铂一起作为共催化剂外,手性
配体还可以选择性地和对映选择性地指导加成反应,双价
配体比单价
配体更受青睐,因为它们具有更强的区域和对映选择性。作为加成反应的氮氧化剂,可以使用
碳酸酯或磺酰胺。如果使用
碳酸酯作为氮氧化剂,则所得的β-羟基
碳酸酯被去保护,以产生相应的β-羟基胺。如果使用磺酰胺作为氮氧化剂,则所得的β-羟基磺酰胺被去保护,以产生相应的β-羟基胺。然后,在第二个合成步骤中,选择性地氧化所得的β-羟基胺,以产生所需的D-和L-
α-氨基酸或D-和L-α-
氨基醛。