Spiro Compounds

8 Chapter 8Figure 8.1 Common strategies for the synthesis of spirocycles: (a) alkylatio...Scheme 8.1 Spirocyclizations reported by Gade.Scheme 8.2 Spirocyclization reported by Takisawa.Scheme 8.3 Spirocyclization reported by Smith.Scheme 8.4 Synthesis of spirocycles reported by Hashimoto et al.Scheme 8.5 Synthesis of spirofuranes and spiropyrrolidines reported by Mikam...Scheme 8.6 Nicolaou synthesis of platensimycin.Figure 8.2 Proposed mechanism for the Rh‐catalyzed synthesis of spirocycles ...Scheme 8.7 Rh–catalyzed synthesis of spirocycles reported by Shintani and Ha...Scheme 8.8 First asymmetric palladium‐catalyzed synthesis of spirocycles.Scheme 8.9 Pd‐catalyzed synthesis of spirocycles reported by Mikami.Scheme 8.10 Pd‐catalyzed spirocyclization of allyl propargyl ethers.Scheme 8.11 Pd‐catalyzed spirocyclization reported by Toste.Scheme 8.12 Spirocyclization reported by Cai.Scheme 8.13 Spirocyclization reported by Dixon.Scheme 8.14 Spirocyclization reported by Luan.Scheme 8.15 [2+2+2] Cycloaddition reported by Shibata et al.Scheme 8.16 [2+2+2] Cycloaddition with unsymmetrical dialkynes.Scheme 8.17 Synthesis of spirocyclanes via a [2+2+2] cycloaddition reported ...Figure 8.3 Proposed mechanism by Tanaka.Scheme 8.18 [2+2+2] Spirocyclization reported by Tanaka.Scheme 8.19 Copper‐catalyzed enantioselective Diels–Alder reaction.Scheme 8.20 [3+2] Cycloaddition reported by C.‐J. Wang.Scheme 8.21 Spirocyclization reported by Deng.Scheme 8.22 Spirocyclizations reported by Trost and Zhao.Scheme 8.23 Spirocyclization reported by Liu.Scheme 8.24 Spirocyclization reported by Rios.Scheme 8.25 Spirocyclization reported by Liu.Scheme 8.26 Enantioselective PET reaction developed by Bach.Scheme 8.27 Synthesis of spirocyclic β‐lactones developed by Romo.Scheme 8.28 Cascade reaction reported by Wang.Scheme 8.29 Spirocyclization reported by Xie.Scheme 8.30 Spirocyclization reported by Chen.Scheme 8.31 Spirocyclization reported by Jørgensen.Scheme 8.32 Spirocyclopropanation of benzofulvenes.Scheme 8.33 Spirocyclization reported by Lin.Scheme 8.34 Spirocyclization reported by Rodriguez and Bonne.Scheme 8.35 Spirocyclization reported by Li.Scheme 8.36 α‐ketol rearrangement reported by Tu.Scheme 8.37 Ring expansion reported by Takisawa.Scheme 8.38 Spirocyclization reported by Zhang.Scheme 8.39 Spirocyclization reported by Zhang.

9 Chapter 9Scheme 9.1 Intramolecular dearomative reaction of para ‐substituted phenol.Scheme 9.2 Proposed dearomative reaction pathway.Scheme 9.3 Preliminary enantioselective construction of all‐carbon spirocent...Scheme 9.4 Synthesis of spiro[4.5]decane core architecture via dearomative s...Scheme 9.5 Iridium‐catalyzed asymmetric allylic dearomatization of phenols....Scheme 9.6 C‐alkylation for ortho ‐substituted naphthols.Scheme 9.7 Intramolecular dearomative reaction of alkyne‐substituted phenol....Scheme 9.8 Intermolecular dearomative spiroannulation of phenol and iodobenz...Scheme 9.9 Strategy for dearomative arylation of phenols.Scheme 9.10 Preliminary results of asymmetric dearomative arylation of pheno...Figure 9.1 Natural erythrina alkaloids.Scheme 9.11 Pd(0)‐catalyzed intramolecular arylative coupling of 5‐hydroxyl ...Scheme 9.12 Preliminary asymmetric studies for constructing erythrinane skel...Scheme 9.13 Proposed one‐step construction of spirocarbocycles and potential...Scheme 9.14 A DYKAT of phenolic derivative via axial‐to‐central chirality tr...Scheme 9.15 Palladium‐catalyzed dynamic kinetic asymmetric transformation.Scheme 9.16 [3+2] Spiroannulation of phenol‐derived biaryls and diynes.Scheme 9.17 Formal [2+2+1] cycloaddition routes to new tricycles.Scheme 9.18 Ru II‐catalyzed dearomative spiroannulation of naphthols via C(spFigure 9.2 Proposed mechanism of C–H bond activation/dearomative reaction.Scheme 9.19 Spiroannulation of 2‐arylphenols via C–H activation/dearomative ...Scheme 9.20 Pd‐catalyzed oxidative dearomatization of free naphthols.Scheme 9.21 [2+2+1] Spiroannulation of unsymmetrical alkynes.Scheme 9.22 Spirocyclopentadienes of 2‐alkenylphenols and alkynes.Scheme 9.23 Spirocyclopentadienes of 2‐alkenylphenols and conjugated enynes....Scheme 9.24 Three‐component dearomatizing [2+2+1] spiroannulation.Scheme 9.25 Preliminary studies on the synthetic application of dearomatizin...Scheme 9.26 Pd/NBE‐catalyzed C–H activation/arene dearomatization reaction....Scheme 9.27 [4+1] Spiroannulation by C(sp 3)‐H activation and naphthol dearom...Scheme 9.28 Ir‐catalyzed asymmetric allylic alkylation for constructing spir...Scheme 9.29 Allylic dearomatization for the synthesis of spiro cyclopentene‐...Figure 9.3 The energetic barrier of transition states.Scheme 9.30 Dearomative arylation of indoles for spiroindolenine derivatives...Scheme 9.31 Dearomatization of C2‐substitued indoles for spirooxindoles.Scheme 9.32 Synthesis of the core structure of phalarine.Scheme 9.33 Process of gold‐catalyzed intramolecular alkyne hydroarylation....Scheme 9.34 Dearomatization of aromatic ynones for spirocyclic scaffolds.Scheme 9.35 One‐pot spirocyclization/trapping to form tetracycles.Scheme 9.36 Scaffolds for the synthesis of spirocyclic indole derivatives.Scheme 9.37 Intermolecular spirocyclization of indoles and propargyl carbona...Figure 9.4 Novel spiroindolenine products.Scheme 9.38 Stepwise synthesis spirocyclic indolines of indoles with allyl a...Scheme 9.39 Pd/NBE‐catalyzed intermolecular dearomative spiroannulation of i...Figure 9.5 Proposed reaction mechanism for palladium‐catalyzed dearomatizati...Scheme 9.40 Asymmetric cycloadditions of vinylcyclopropanes with indoles.Scheme 9.41 Allylic dearomatization of pyrroles for six‐membered spiro‐2H‐py...Scheme 9.42 Arylative dearomatization of pyrroles for six‐membered spiro‐2H‐...Figure 9.6 Selected bioactive compounds bearing spironaphthalene‐pyrrolidine...Scheme 9.43 Allylic dearomatization of pyrroles for five‐membered spiro‐2H‐p...Figure 9.7 Quantitative formation of spirocycles from 3‐pyrroles.Scheme 9.44 Intramolecular nucleophilic dearomatization of furans.Scheme 9.45 Dearomatizing 2,5‐alkoxyarylation of furan rings for spirooxindo...Scheme 9.46 Three possible pathways for the formation of 142a.Scheme 9.47 Mechanistic experiments for dearomatizing 2,5‐alkoxyarylation of...Scheme 9.48 Further transformations of spiro π‐allyl palladium.Scheme 9.49 Synthesis of spiroacetals from boronic acids and hydroxyalkylfur...Scheme 9.50 Synthesis of thiophene‐containing spirocyclic products via C–H a...Scheme 9.51 Cu(II)‐promoted transformations of α‐thienylcarbinols into spiro...Scheme 9.52 Synthesis of halogenated spirothienooxindoles from 159aand 158aScheme 9.53 Intermolecular Heck‐type dearomative [2+2+1] spiroannulation of ...Scheme 9.54 Palladium‐catalyzed aryne insertion/arene dearomatization to spi...Scheme 9.55 Mechanism studies for the 5‐exo‐trig spiroannulation...Scheme 9.56 Intramolecular asymmetric allylic dearomatization of benzene der...Scheme 9.57 A Cu‐catalyzed Sommelet–Hauser dearomatization of dihydrophenant...Scheme 9.58 Substituent effects.

10 Chapter 10Figure 10.1 Fenestrane motifs and their multifariousness. Top: (a) A stylist...Figure 10.2 From spiranes to fenestranes and beyond. Top: Spiro[4.4]nonane (Scheme 10.1 Retrosynthetic approach to the [5.5.5.5]fenestrane skeleton from...Figure 10.3 Systematic extensions of Keese’s parent all‐ cis ‐[5.5.5.5]fenestr...Scheme 10.2 Keese’s first synthesis of all‐ cis ‐[5.5.5.5]fenestrane ( 2).Scheme 10.3 Cook’s first‐reported synthesis of all‐ cis ‐[5.5.5.5]fenestra‐2,5...Scheme 10.4 Three hypothetical functionalized spiro structures as starting p...Scheme 10.5 Synthesis of 1,3‐indanediol 24and [2,2′]spirobiindane‐1,1′‐diol...Scheme 10.6 Attempted construction of the benzoannelated [5.6.6.6]fenestrane...Scheme 10.7 Synthesis of the benzoannelated [5.5.5.6]fenestranes with cis , ci ...Scheme 10.8 Unsuccessful attempts to synthesize fenestrindane 7along the fu...Scheme 10.9 Naphthoannelated all‐ cis ‐[5.5.5.6]fenestranones 51and 53‐ 55acc...Figure 10.4 The first benzoannelated [5.5.5.6]fenestranones bearing two ( 56)...Scheme 10.10 Construction of extended benzoannelated fenestrane derivatives ...Scheme 10.11 Top: Both the stereoisomeric tetramethyl‐substituted [5.5.5.6]f...Scheme 10.12 Synthesis of the bis‐(pentaarylphenyl)fenestrindane 82from the...Scheme 10.13 Synthesis of saddle‐shaped fourfold bay‐bridged fenestrindane 9...Figure 10.5 The parent fenestrindane saddle 10and its octamethoxy derivativ...Figure 10.6 Solid‐state structure of the fourfold bay‐bridged fenestrindane Scheme 10.14 Access to centrohexaindanes via the “broken fenestrane route” a...Figure 10.7 Solid‐state molecular structure of tetramethoxycentrohexaindane Figure 10.8 Selected derivatives of centrohexaindane ( 9) in a perspective pr...Figure 10.9 The four constitutional isomers of hexanitrocentrohexaindane, 10...Figure 10.10 Dodecafunctionalized centrohexaindanes 105– 107, synthesized by ...Figure 10.11 Solid‐state molecular structure of dodecaphenylcentrohexaindane...Figure 10.12 Two hypothetical extensions of the centrohexaindane core, model...