An Enantioselective Total Synthesis of (−)‐Isoschizogamine

Abstract

Ac oncise enantioselective total synthesis of (À)-isoschizogamine, ac omplex bridged polycyclic monoterpene indole alkaloid, was accomplished. N-Alkylation of an enantio-enriched imine with an alkyli odide afforded an iminium salt, which, upon heating by microwave irradiation in the presence of pivalic acid, was converted into the hexacyclic structure of natural product by acomplex but ordered domino sequence.The one-pot process leading to the formation of one C À Cbond and three C À Nbonds created three rings and three contiguous stereogenic centers with complete control of both the relative and absolute stereochemistry.

Advances in Stereoconvergent Catalysis from 2005 to 2015: Transition-Metal-Mediated Stereoablative Reactions, Dynamic Kinetic Resolutions, and Dynamic Kinetic Asymmetric Transformations

“…More recently, in 2015 Zhu and coworkers reported the total synthesis of (−)-isoschizogamine ( 41 ) that utilized a stereoablative, enantioselective cyclopentanone allylic alkylation. 40 Given the power of this method for the construction of valuable all-carbon quaternary stereocenters, it is likely that we will continue to witness its use in natural product total synthesis for years to come.…”

Formal [4+1] Cycloaddition of o‐Aminobenzyl Chlorides with Isocyanides: Synthesis of 2‐Amino‐3‐Substituted Indoles

“…The cyclic carbamate of type 1i (Figure 1) is also known to be a suitable precursor of aza-ortho-xylylene and has been successfully used in the synthesis of complex natural product. [58] However, no reaction occurred when 1i and 2a was treated under standard reaction conditions due to the high stability of 1i. Heating the mixture led only to the decomposition of the reactants.…”

Asymmetric Brønsted Acid Catalyzed Substitution of Diaryl Methanols with Thiols and Alcohols for the Synthesis of Chiral Thioethers and Ethers

“…[1] Thefacile access they offer to tetrahydroquinolines and indoles, [2,3] as well as their increasing utilization in complex natural product syntheses (e.g. [6] Nevertheless,a za-ortho-quinone methides,especially compared to their oxygen-containing analogous ortho-quinone methides, [7] have not been adequately investigated to date.P articularly in the area of asymmetric synthesis,only afew examples exist. [6] Nevertheless,a za-ortho-quinone methides,especially compared to their oxygen-containing analogous ortho-quinone methides, [7] have not been adequately investigated to date.P articularly in the area of asymmetric synthesis,only afew examples exist.…”

“…virantmycin [4] and chartellin [5] ), have led to an increased awareness of these scaffolds. [6] Nevertheless,a za-ortho-quinone methides,especially compared to their oxygen-containing analogous ortho-quinone methides, [7] have not been adequately investigated to date.P articularly in the area of asymmetric synthesis,only afew examples exist. [8] Fort he in situ generation of aza-ortho-quinone methides various methods have been proven of value,among them the base-induced 1,4-elimination of ortho-chloromethyl aniline derivatives, [2][3][4]9] thermally induced dehydration of benzyl alcohols, [10] and photochemically induced enolizations of ortho-carbonyl anilides.…”