Asymmetric Construction of Polycyclic Indoles through Olefin Cross‐Metathesis/Intramolecular Friedel–Crafts Alkylation under Sequential Catalysis

Abstract

Scheme 1. Cascade reaction involving cross-metathesis and an asymmetric Friedel-Crafts alkylation. Boc = tert-butoxycarbonyl.

Recent Advances in Multicatalyst Promoted Asymmetric Tandem Reactions

“…[29] They reported a practical and economical synthesis of tetrahydropyranoA C H T U N G T R E N N U N G [3,4-b]indols and tetrahydro-b-carbollines by the combination of Ru catalyzed olefin cross-metathesis and a chiral Brønsted acid catalyzed Friedel-Crafts alkylation reaction (see Scheme 22). This tandem reaction allows the use of readily available starting materials to highly enantioselectively construct synthetically valuable polycyclic indole frameworks.…”

Synthesis of Cyclic Peptides and Peptidomimetics by Metathesis Reactions

“…Based on an initial screening [137], ring-closing metathesis of 102a was performed with M1 [140] (30 mol%) and gave 101a in 91% yield, while RCM in the presence of Zhan-1B [141] (10 mol%) resulted in the isolation of 101a in 98% yield. Despite the high yields, high catalyst loading and high dilution conditions (<3 mM) were required.…”

“…As the fifth example [179], RCM was applied to constrain and simplify caspofungin (141) as an antifungal peptide that belongs to the class of echinocandins that act by inhibiting the β-(1,3)-D-glucan synthase complex [180].…”

Relay Catalysis Using a Rhodium Complex/Chiral Brønsted Acid Binary System: Enantioselective Reduction of a Carbonyl Ylide as the Reactive Intermediate

“…Table 3 summarizes experiments carried out to probe the scope of the present transformation. Investigation of the effect of the substituent on the Ar group showed that comparable enantioselectivities were observed irrespective of the electronic character and position of the substituent introduced on the phenyl ring (Table 3, entries [1][2][3][4][5]. The a-diazocarbonyl compounds 3 having substituents on the basal aromatic ring also underwent the consecutive transformation to afford isochromene derivatives 6 in good yields (Table 3, entries 6 and 7).…”