Catalytic asymmetric hydrosilylation of acetophenone with new chiral thiourea ligands containing the (S)-α-phenylethyl group

Bis‐thiourea Derivatives and Their Utility in Synthesis of Mono‐heterocyclic, Bis‐heterocyclic, and Fused Heterocyclic Systems

“…The bis‐thiourea derivatives 16 and 19 were prepared in high yields from reaction of the 1,2‐diamine 13 or 17 , respectively, with 2 equiv of the appropriate isothiocyanate 15 or 18 in DCM at 25°C (Scheme ) . The obtained bis‐thiourea derivatives 16 and 19 were used as chiral ligands in some zinc‐based‐catalyzed hydrosilylation of acetophenone.…”

Non‐Redox‐Metal‐Catalyzed Redox Reactions: Zinc Catalysts

“…Based on this study, several other chiral diamines have also been developed for the enantioselective reduction of ketones. [14][15][16][17][18][19][20][21][22] The group of Carpentier reported a complementary study on Mimoun's catalyst system (Scheme 2 b). [15,16] Their new diamine ligand achieved 91 % ee and 66 % yield; comparably, the previously reported diamine ligands gave > 99 % yield with 76-88 % ee.…”

Mechanism and Enantioselectivity of [Zinc(diamine)(diol)]‐Catalyzed Asymmetric Hydrosilylation of Ketones: DFT, NMR and ECD Studies

“…[24][25][26][27] We [24] and others [28] have recently reported that chiral hexamine macrocycles (trianglamines) [29] derived from DACH, in complexes with diethylzinc, efficiently cata-lyze asymmetric hydrosilylation of aryl alkyl ketones with enantiomeric excess of the product of up to 89 %. [24][25][26][27] We [24] and others [28] have recently reported that chiral hexamine macrocycles (trianglamines) [29] derived from DACH, in complexes with diethylzinc, efficiently cata-lyze asymmetric hydrosilylation of aryl alkyl ketones with enantiomeric excess of the product of up to 89 %.…”

“…Enantiomerically pure trans-1,2-diaminocyclohexane (DACH) is particularly valuable because it can be used as a highly flexible source of diamine structures as well as in various chiral complexes with N,N-or N,S-chelating ligands. [24][25][26][27] We [24] and others [28] have recently reported that chiral hexamine macrocycles (trianglamines) [29] derived from DACH, in complexes with diethylzinc, efficiently cata-and the substrate, took place through Zn-activation of the carbonyl group. The absolute stereochemistry of the final product predicted on the basis of our proposal is in agreement with the available experimental data.…”