Design and Synthesis of Rigid-Featured Tertiary Amine-Derived C2-Symmetric Chiral Furan-N,N′-dioxide Ligands

• Published in: European journal of organic chemistry Vol. 26; no. 42
• Main Authors: Chen, Zi-Yue, Hu, Pan, Wang, Xi-Rui, Xu, Ke-Lan, Wang, Yu-Heng, Tian, You-Ping, Zhou, Ying, Liu, Xiong-Li
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 07.11.2023; Wiley Subscription Services, Inc
• Subjects: Alkylation; Chemistry; Chemistry, Organic; Dioxides; Ligands; Nitrogen; Physical Sciences; Science & Technology; chiral N-oxides; CATALYSIS; IMINO ESTERS; SYMMETRY; PINCER LIGANDS; CONSTRUCTION; L-lprolinamides; SELECTIVE 3+2 CYCLOADDITION; chiral furan-N,N'-dioxideligands; N-OXIDES; Friedel-Crafts reaction; chiral furan-containing ligands
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.202300764

To expand the chemical space of chiral N-oxides and chiral furan-containing ligands, herein we designed and synthesized a new class of rigid-featured tertiary amine-derived C-2-symmetric chiral furan-N,N'-dioxide (Fu-2NO) ligands from optically pure lprolinamides/hydroxylprolinamides in operationally simple two steps and up to 57% overall yield. The newly developed rigidfeatured chiral Fu-2NO ligands possesses two pyrroloimidazolone-based N-oxides as non-flat chiral walls, and afforded the opportunity for fine-tuning the ligand electronic and conformational properties by judicious choice of the substituent in the nonligating nitrogen atom. More importantly, The Fu-2NO ligands can tolerate air and moisture such that no special handling is needed for their storage, and can be applied in the Ni(II)-catalyzed asymmetric Friedel-Crafts alkylation reaction of indole.