Enantioselective Aldol Reaction of Tin Enolates with Aldehydes Catalyzed by BINAP·Silver(I) Complex

Silver Phosphanes Partnered with Carborane Monoanions: Synthesis, Structures and Use as Highly Active Lewis Acid Catalysts in a Hetero-Diels–Alder Reaction

“…[24,25] Concurrently, there is also interest in Lewis acid catalysis using silver(i) salts as effective promoters of a wide-range of organic transformations including allylation, aldol, ene and glycosylation reactions. [34] Of particular note is the use of silver(i) BINAP ([1,1'-binaphthalene]-2,2'-diylbis(diphenylphosphane)) complexes in asymmetric aldol reactions, [35±38] Mukaiyama aldol reactions, [39] asymmetric allylations [40] and hetero-Diels ± Alder reactions. [41] It is well established that these reactions are accelerated by other Lewis acids (for example: Ti, B, Al, Sn complexes).…”

Poor enantioselectivity of the direct aldol reaction catalyzed by (S,S)‐proline dipeptide: A density functional study

“…The C(12)-N(9)-C(5)-C(13) dihedral angles in anti-and syn-enamines are Ϫ157.9°and Ϫ147.9°, respectively, which shows that the hybridization at N(9) is indeed between sp 3 and sp 2 . Natural population analysis gives the charges on N(9) in anti-and syn-enamines are Ϫ0.4837 e and Ϫ0.4792 e, respectively.…”

“…The aldol reaction is an important carbon-carbon bond forming reaction in organic chemistry. It is typically accomplished with an enolate, a chiral transition-metal catalyst [1][2][3][4], or a natural aldolase enzyme [5][6][7]. However, the direct aldol reaction between unmodified carbonyls would be the most attractive synthetic alternative.…”

Aldol and Related Processes

“…15 In 1997, Yamamoto, Yanagisawa, and others reported the asymmetric reaction catalyzed by a BINAP-AgOTf catalyst (Table 9.7). 16 The reaction was conducted with tributyltin enolate and aldehydes in the presence of the BINAP-AgOTf catalyst to afford the corresponding adduct with high enantioselectivity. The observed anti : syn ratio depended on the E : Z ratio of enolate, and this result suggested the cyclic transition state (Fig.…”