Highly stereoselective synthesis of spirocyclopropylthiooxindoles and biological evaluation

We present a novel highly stereoselective Rh-catalyzed cyclopropanation of diazothiooxindoles with a broad range of α-functionalized styrenes, enabling facile access of chiral spirocyclopropylthiooxindoles in high to excellent enantiomeric excess.

Rapid synthesis of spirodienones via electrochemical dearomative spirocyclization in flow

An electrochemical dearomative spirocyclization in flow has been developed, featuring the use of electrons as the clean oxidant in a minimum amount of electrolytes to afford diverse spirodienones in a short reaction time.

Dinuclear zinc catalyzed asymmetric [3 + 2] spiroannulation for the synthesis of diverse bispirocyclic saccharines

A highly atom-economical and novel enantioselective [3 + 2] spiroannulation reaction of saccharine-derived cyclic 1-azadienes with α-hydroxy-1-indanones has been developed.

Recent Advances in the Transition Metal-Free Synthesis of Heterocycles from α, β-Unsaturated Ketones

Heterocyclic compounds are an inevitable part of our life. These important classes of molecules have a wide range of applications starting from life-sustaining drugs to agrochemicals. Numerous methods, including metal...

Rh(III)-catalyzed C-H bond activation/annulation reactions of arylacyl ammonium salts with 4-diazoisochroman-3-imines and 4-diazoisoquinolin-3-ones

We report a C-H bond functionalization strategy for the construction of oxo- and aza-spirocyclic compounds from diazo compounds as coupling partners. Our method comprises ortho sp2 C-H bond activation of...

Zinc-catalyzed asymmetric [3 + 2] annulations for construction of chiral spiro[1-indanone-γ-butyrolactones] via a C−N bond cleavage process

An intriguing tandem Michael/lactonization reaction of α-hydroxy-1-indanones and methyleneindolinones has been established in this work. The employ of chiral dinuclear zinc catalysts is essential in achieving highly efficient chirality transfer...

Catalytic asymmetric construction of dispirotriheterocyclic structures through [3+2] cycloadditions of 4-amino pyrazolone-based azomethine ylides

An efficient and convenient catalytic asymmetric [3+2] cycloaddition of 4-amino pyrazolone-based azomethine ylides was developed, which delivers the multi-pharmacophore-containing dispirotriheterocyclic scaffolds with excellent stereoselectivities.

Coupling partner-dependent unsymmetrical C–H functionalization of N-phenoxyacetamides leading to sophisticated spirocyclic scaffolds

In this paper, a coupling partner-dependent unsymmetrical C–H functionalization of N-phenoxyacetamides leading to the formation of sophisticated spirocyclic scaffolds is presented.

Synthesis of functionalized 3,2′-pyrrolidinyl spirooxindoles via domino 1,6-addition/annulation reactions of para-quinone methides and 3-chlorooxindoles

A highly efficient diastereoselective [4 + 1] cycloaddition of ortho-tosylaminophenyl-substituted p-QMs with 3-chlorooxindoles has been developed to afford 3,2′-pyrrolidinyl spirooxindoles.

Synthesis of Spiroindolenine Bearing Chroman Scaffolds Based on Cylization Reaction to para-Methylated Methides

An efficient diastereoselective cyclization reaction of ortho-hydroxyphenyl-substituted para-quinone methides with α,β-unsaturated imines generated in situ from aryl sulfonyl indoles was developed, which afforded spiroindolenine bearing chroman scaffolds in good to...

DFT study on the gold(I)-catalyzed cycloaddition and rearrangement reactions of allene-containing allylic silyl ether

The DFT calculation at the B3LYP/B3LYP-D3(BJ) level was carried out to explore the reaction mechanism of the synthesis of spirocyclo[4,5]decane skeleton by gold-catalyzed allenyl compounds. The more accurate energy under the CH₃CN solvent in the experiment is calculated by the single-point energy of the SMD model. Computational studies have shown that the reaction consists of three main steps: intramolecular cycloaddition of the end group carbon atoms of allenyl and vinyl groups, the semipinacol rearrangement process in which the four-membered ring is reconstructed into the five-membered ring, the elimination reaction releases the catalyst and obtains the product. The calculation results show that Zheng et al. reported that the gold-catalyzed synthesis reaction can easily occur under the experimental conditions due to its low activation free energy (12.07-15.49 kcal/mol). Furthermore, it was found that the MOMO(CH₂)₂ substituent has higher reactivity than the corresponding reactant of the phenyl substituent.

Chemoselective Synthesis of Sulfenylated Spiroindolenines from Indolyl-ynones via Organosulfenyl Chloride-Mediated Dearomatizing Spirocyclization

A metal-free sulfenylation/spirocyclization of indolyl-ynones realized by organosulfenyl chloride, generated in situ from the reaction of disulfides and PhICl₂, is presented. This cascade one-pot process enables a chemoselective synthesis of diverse sulfenylated spiroindolenines depending on the substituent pattern at the two-position of indolyl-ynones.

Enantioselective Construction of Chiral Bispiro[Oxindole-Pyrrolidine-Pyrazolone] Derivatives via Sequential and One-Pot Mannich/Hydroamination Reaction

The atom-economic method for the preparation of novel bispirocyclic compounds containing three fused heterocyclic scaffolds privileged in drug discovery was developed by using a chiral amine-squaramide Mannich reaction and Au(I)-catalyzed hydroamination. The developed synthetic strategy performed either stepwise or as a one-pot process allows the formation of chiral bispirocyclic [oxindole-pyrrolidine-pyrazolones] in high yields (up to 75%) with excellent enantioselectivities (up to 99%).

[3+2] regioselective annulation reaction of 2-arylidene-1,3-indandiones towards synthesis of spirocyclopentenes: understanding the mechanism of γ-attack vs. α-attack using DFT studies

A regioselective [3+2] cyclisation reaction between 2-arylidene-1,3-indanedione and ethyl 2,3-butadienoate catalysed by triphenylphosphine has been demonstrated to synthesize functionalised spirocyclic cyclopentenes. The reaction tolerated various electron-rich and electron-deficient aryl substituted 2-arylidene-1,3-indanediones with high to excellent chemical yields (up to 99%) and moderate to good regioselectivity (up to 5 : 1). DFT studies have also been carried out to understand the regioselective nature of this reaction. The results of Frontier molecular orbital calculations and the activation energy (E a) favour the formation of compound 3avia γ-attack compared to that of 4avia α-attack.

Asymmetric Direct/Stepwise Dearomatization Reactions Involving Hypervalent Iodine Reagents

A remarkable growth in hypervalent iodine-mediated oxidative transformations as stoichiometric reagents as well as catalysts has been well-documented due to their excellent properties, such as mildness, easy handling, high selectivity, environmentally friendly nature, and high stability. This review aims at highlighting the asymmetric oxidative dearomatization reactions involving hypervalent iodine compounds. The present article summarizes asymmetric intra- and intermolecular dearomatization reactions using chiral hypervalent iodine reagents/catalysts as well as hypervalent iodine-mediated dearomatization reactions followed by desymmetrization.

Lewis acid-catalyzed [3 + 2] annulations of oxindole based spirocyclic donor-acceptor cyclopropanes with ynamides

[3 + 2] annulations of oxindole based spirocyclic donor-acceptor cyclopropanes and ynamides catalyzed by copper triflate have been developed for the synthesis of biologically important spirocyclopenteneoxindoles. These reactions tolerated a wide scope of substrates and provided the desired products in good to high yields (up to 90%) with up to >40 : 1 diastereoselectivities under mild conditions.

Enantio- and Diastereodivergent Synthesis of Spirocycles through Dual-Metal-Catalyzed [3+2] Annulation of 2-Vinyloxiranes with Nucleophilic Dipoles

The development of efficient and straightforward methods for obtaining all optically active isomers of structurally rigid spirocycles from readily available starting materials is of great value in drug discovery and chiral ligand development. However, the stereodivergent synthesis of spirocycles bearing multiple stereocenters remains an unsolved challenge owing to steric hindrance and ring strain. Herein, we report an enantio- and diastereodivergent synthesis of rigid spirocycles through dual-metal-catalyzed [3+2] annulation of oxy π-allyl metallic dipoles with less commonly employed nucleophilic dipoles (imino esters). A series of spiro compounds bearing a pyrroline and an olefin were easily synthesized in an enantio- and diastereodivergent manner (up to 19:1 dr, >99 % ee), which showed great promise as a new type of N-olefin ligand. Preliminary mechanistic studies were also carried out to understand the process of this bimetallic catalysis.

Catalytic enantioselective synthesis of chiral spirocyclic 1,3-diketones via organo-cation catalysis

An SPA-triazolium bromide-catalyzed transannular C-acylation of enol lactones is presented. This methodology provides convenient access to a range of enantioenriched spirocyclic 1,3-diketones in moderate to high yields and enantioselectivities and features a broad substrate scope in terms of enol lactones. The catalytic capability of this triazolium salt catalyst is also demonstrated in this enantioselective transformation, which could inspire its further application.

Synthesis of Chiral Spirolactams via Sequential C-H Olefination/Asymmetric [4+1] Spirocyclization under a Simple CoII /Chiral Spiro Phosphoric Acid Binary System

An unprecedented enantioselective synthesis of spiro-γ-lactams via a sequential C-H olefination/asymmetric [4+1] spirocyclization under a simple Co^II /chiral spiro phosphoric acid (SPA) binary system is reported. A range of biologically important spiro-γ-lactams are obtained with high levels of enantioselectivity (up to 98 % ee). The concise, asymmetric synthesis of an aldose reductase inhibitor was successfully achieved. Notably, contrast to previous reports that relied on the use of cyclopentadienyl or its derivatives (achiral Cp*, Cp^tBu , or chiral Cp^x ) ligated Co^III complexes requiring tedious steps to prepare, cheap and commercially available cobalt(II) acetate tetrahydrate was used as an efficient precatalyst.

Stereoselective Access to Spirooxindoles and Bisoxindoles Through Organocatalyzed Asymmetric Divergent Transformations of Isatin-derived MBH Carbonates

An interesting β-isoquinidine catalyzed divergent reaction was developed to produce either spirocyclopentene oxindoles, spirocyclopentadiene oxindoles or bisoxindoles in a high enantioselective fashion. The utility of this protocol was demonstrated by the versatile transformations of the products. This work not only represents the first highly stereoselective intermolecular catalytic asymmetric allylic alkylation reaction between two isatin-derived MBH carbonate molecules but also constitutes a rare example of isatin-derived MBH carbonate-based enantioselective and α-regioselective [3+2] cycloaddition reactions.

A bifunctional squaramide-catalysed enantioselective vinylogous Michael addition/cyclization cascade reaction of 4-unsaturated isoxazol-5-ones and α,α-dicyanoalkenes

An effective strategy for the stereoselective synthesis of spiro isoxazolone-cyclohexenimines was developed using a bifunctional squaramide-catalysed vinylogous Michael addition/cyclization cascade reaction of 4-unsaturated isoxazol-5-ones and α,α-dicyanoalkenes. The atom-economical cascade process can proceed smoothly under extremely low catalyst loading (1 mol%) and mild conditions, and the corresponding products were obtained in moderate to good yields (45% to 90%) and enantioselectivitites (51% to 96% ee). Meanwhile, the scale-up reaction and transformation of the products were also demonstrated.

New Methods for the Synthesis of Spirocyclic Cephalosporin Analogues

Spiro compounds provide attractive targets in drug discovery due to their inherent three-dimensional structures, which enhance protein interactions, aid solubility and facilitate molecular modelling. However, synthetic methodology for the spiro-functionalisation of important classes of penicillin and cephalosporin β-lactam antibiotics is comparatively limited. We report a novel method for the generation of spiro-cephalosporin compounds through a Michael-type addition to the dihydrothiazine ring. Coupling of a range of catechols is achieved under mildly basic conditions (K2CO3, DMF), giving the stereoselective formation of spiro-cephalosporins (d.r. 14:1 to 8:1) in moderate to good yields (28-65%).

Direct access to spirocycles by Pd/WingPhos-catalyzed enantioselective cycloaddition of 1,3-enynes

Spirocycles play an important role in drug discovery and development. The direct, catalytic, and enantioselective synthesis of spirocycles from readily available starting materials and in an atom economic manner remains a highly sought-after task in organic synthesis. Herein, an enantioselective Pd-hydride-catalyzed cycloaddition method for the synthesis of spirocyclic compounds directly from two classes of commonly available starting materials, 1,3-enynes and cyclic carbon−hydrogen (C−H) bonds, is reported. The reactions employ a chiral Pd/WingPhos catalyst to both suppress the formation of bis-allenyl by-products and control the stereoselectivity. 1,3-Enynes are used as dielectrophilic four-carbon units in the cycloaddition reactions, which also enables an enyne substrate-directed enantioselectivity switch with good levels of stereocontrol. The present spirocycle synthesis tolerates a broad range of functional groups of 1,3-enyne substrates, including alcohols, esters, nitriles, halides, and olefins. A variety of diverse cyclic nucleophiles, including pharmaceutically important heterocycles and carbocycles, can be flexibly incorporated with spiro scaffolds.

Spirocycles are traditionally difficult structures to synthesize due to the congested nature of the central atom. Here the authors show a method to synthesize quaternary carbon spirocycles in one step from 1,3-enynes and pyrazolidine-type heterocycles, both relatively unactivated structures, proceeding via palladium catalysis.

Desymmetrization of Cyclic 1,3-Diketones under N-Heterocyclic Carbene Organocatalysis: Access to Organofluorines with Multiple Stereogenic Centers

Symmetric 1,3-diketones with fluorine or fluorinated substituents on the prochiral carbon remain to be established. Herein, we have developed a novel prochiral fluorinated oxindanyl 1,3-diketone and successfully applied these substrates in carbene-catalyzed asymmetric desymmetrization. Accordingly, a versatile strategy for asymmetric generation of organofluorines with fluorine or fluorinated methyl groups has been developed. Multiple stereogenic centers were selectively constructed with satisfactory outcomes. Structurally diverse enantioenriched organofluorines were generated with excellent results in terms of yields, diastereoselectivities, and enantioselectivities. Notably, exchanging fluorinated methyl groups to fluorine for this prochiral 1,3-diketones leads to switchable stereoselectivity. Mechanistic aspects and origin of stereoselectivity were studied by DFT calculations. Notably, some of the prepared organofluorines demonstrated competitive antibacterial activities.

An update on the progress of cycloaddition reactions of 3-methyleneindolinones in the past decade: versatile approaches to spirooxindoles

Cycloaddition reactions are of great interest due to their potential and rapid construction of optically enriched spiro-cyclic products. 3-Methyleneindolinones have been proven to be a valuable precursor in cycloaddition reactions for the construction of diverse 3,3'-spirocyclic oxindoles. Their versatile reactivity has provided a new forum for the development of a variety of building blocks and synthetic compounds, including bioactive molecules. Herein, significant accomplishments in the cycloaddition reactions of 3-methyleneindolinones for the synthesis of spirooxindoles have been summarised and elaborated. The review is outlined according to the type of cycloaddition such as [2 + 1], [2 + 2], [3 + 2], [4 + 2] and [5 + 2] cycloaddition reactions.

Organocatalytic Asymmetric Synthesis of Spirooxindole Embedded Oxazolidines

The first organocatalytic asymmetric synthesis of spirooxindole embedded oxazolidines has been developed via a domino reaction involving hemiaminal formation, followed by an unprecedented aza-Michael reaction between isatin derived N-Boc ketimines and γ-hydroxy enones. A quinine derived bifunctional squaramide catalyst was found to be efficient for this reaction, and the products were obtained in good diastereoselectivity and with high enantioselectivity.

Application of chiral triazole-substituted iodoarenes in the enantioselective construction of spirooxazolines

A catalytic highly enantioselective synthesis of spirooxazolines is presented. Starting from readily available 2-naphthol-substituted benzamides and using catalytic amounts of a chiral triazole-substituted iodoarene catalyst, a variety of spirooxazolines can be isolated through an enantioselective oxidative dearomatization in up to 92% yield and 97% ee. The further synthetic utility of the optically enriched spirooxazolines was examined providing a corresponding 2-naphthalenole and an oxepin.

Recent applications of asymmetric organocatalytic annulation reactions in natural product synthesis

The past two decades have witnessed remarkable growth of asymmetric organocatalysis, which is now a firmly established synthetic tool, serving as a powerful platform for the production of chiral molecules. Ring structures are ubiquitous in organic compounds, and, in the context of natural product synthesis, strategic construction of ring motifs is often crucial, fundamentally impacting the eventual fate of the whole synthetic plan. In this review, we provide a comprehensive and updated summary of asymmetric organocatalytic annulation reactions; in particular, the application of these annulation strategies in natural product synthesis will be highlighted.

Enantioselective Synthesis of Spiropyrazolone-Fused Cyclopenta[c]chromen-4-ones Bearing Five Contiguous Stereocenters via (3+2) Cycloaddition

An enantioselective synthesis of spiropyrazolone-fused cyclopenta[c]chromen-4-ones is demonstrated via a (3+2) cycloaddition reaction. The reactions of 3-homoacylcoumarins and α,β-unsaturated pyrazolones in the presence of the cinchona-alkaloid derived hydrogen-bonding catalyst provide aforementioned spiropyrazolone-chromenone adducts bearing five contiguous stereocenters, of which one is the spiro all-carbon quaternary stereocenter in high yields (up to 98%) with good to excellent stereoselectivities (>25:1 dr and up to 99% ee). This one-pot methodology could also be practically demonstrated on a gram-scale with similar efficacy.

Divergent Reactivity of δ- and β'-Acetoxy Allenoates with 2-Sulfonamidoindoles via Phosphine Catalysis: Entry to Dihydro-α-carboline, α-Carboline, and Spiro-cyclopentene Motifs

The reactivity of 2-sulfonamidoindoles with acetoxy allenoates under phosphine catalysis depends on the disposition of the acetoxy (OAc) group on the allenoate. In the temperature-controlled [3 + 3] annulations, δ-acetoxy allenoates afforded dihydrocarboline and carboline scaffolds with carbon-nitrogen nucleophilic 2-sulfonamidoindoles, in which allenoate serves as a β-, γ-, and δ-carbon donor. At room temperature (25 °C), dihydro-α-carboline motifs were obtained exclusively through Michael addition, 1,4-proton shift, isomerization, 1,2-proton transfer, phosphine elimination, and aza-Michael addition. The higher temperature (80 °C) cascade protocol using Ph₃P-Cs₂CO₃ combination involves addition-elimination, aza-Claisen rearrangement, tosyl migration, and aromatization as key steps to give α-carbolines containing tosyl functionality at the γ-carbon. In contrast, with β'-acetoxy allenoate, 2-sulfonamidoindole acts only as a carbo-nucleophile in (p-tolyl)₃P-directed [4 + 1] spiro-annulation, leading to five-membered spiro-carbocyclic motifs essentially as single diastereomers (dr >20:1) via chemoselective carbo-annulation.

Rhodium(iii)-catalyzed asymmetric [4+1] spiroannulations of O-pivaloyl oximes with α-diazo compounds

Chiral Rh^III catalysts can catalyze the asymmetric [4+1] spiroannulation of O-pivaloyl oximes with α-diazo homophthalimides under redox-neutral and acid/base-neutral conditions, leading to formation of chiral spirocyclic imines as a result of C-H activation and N-O cleavage. The reaction proceeded with high efficiency and features broad substrate scope, mild reaction conditions, and high to excellent enantioselectivities.

Synthesis of CF3-Containing Spirocyclic Indolines via a Red-Light-Mediated Trifluoromethylation/Dearomatization Cascade

A red-light-mediated ⁿPr-DMQA⁺-catalyzed cascade intramolecular trifluoromethylation and dearomatization of indole derivatives with Umemoto's reagent has been developed. This protocol provides a facile and efficient approach for the construction of functionalized and potentially biologically important CF₃-containing 3,3-spirocyclic indolines with moderate to high yields and excellent diastereoselectivities under mild conditions. The success of multiple gram-scale (1 and 10 g) experiments further highlights the robustness and practicality of this protocol and the merit of the employment of red light. Mechanistic studies support the formation of a crucial CF₃ radical species and a dearomatized benzyl carbocation intermediate.

Enantioselective and Diastereodivergent Synthesis of Spiroindolenines via Chiral Phosphoric Acid-Catalyzed Cycloaddition

A diastereodivergent and enantioselective synthesis of chiral spirocyclohexyl-indolenines with four contiguous stereogenic centers is achieved by a chiral phosphoric acid-catalyzed cycloaddition of 2-susbtituted 3-indolylmethanols with 1,3-dienecarbamates. Modular access to two different diastereoisomers with high enantioselectivities was obtained by careful choice of reaction conditions. Their functional group manipulation provides an efficient access to enantioenriched spirocyclohexyl-indolines and -oxindoles. The origins of this stereocontrol have been identified using DFT calculations, which reveal an unexpected mechanism compared to our previous work dealing with enecarbamates.

Synthesis of Succinimide Spiro-Fused Sultams from the Reaction of N-(Phenylsulfonyl)acetamides with Maleimides via C(sp2)-H Activation

Presented herein is an effective preparation of succinimide spiro-fused sultams through the coupling reaction of N-(phenylsulfonyl)acetamides with maleimides. It is deduced that this reaction should proceed through a cascade process including Rh(III)-catalyzed C(sp²)-H bond cleavage of N-(phenylsulfonyl)acetamide, maleimide double bond insertion into the C-Rh bond, β-hydride elimination, reductive elimination, and intramolecular aza-Michael addition. Notably, this cascade procedure features simultaneous annulation and spirocyclization through traceless fusion of the directing group into target product by using air as an economical oxidant to assist the regeneration of the active Rh(III) catalyst. This new method has several advantages including readily accessible starting materials with broad scope, significantly reduced synthetic steps, redox-neutral conditions, high atom-economy, and sustainability.

Divergent Metal-Free [4 + 2] Cascade Reaction of 1-Indanylidenemalononitrile with 3-Benzylidenebenzofuran-2(3H)-one: Access to Spiro-dihydrofluorene-benzofuranone and Axially Chiral Fluorenylamine-phenol Derivatives

An efficient cascade reaction of 1-indanylidenemalononitrile with 3-benzylidenebenzofuran-2(3H)-one divergently promoted by DABCO or chiral organocatalyst was developed under mild reaction conditions, and various spiro-dihydrofluorene-benzofuranones were produced in gratifying results, respectively. It is worth noting that both the spiro and axially chiral products can be obtained by tuning the reaction conditions. The mechanism of the transformation was also studied by quantum chemical calculations.

Catalytic System-Controlled Divergent Reaction Strategies for the Construction of Diversified Spiropyrazolone Skeletons from Pyrazolidinones and Diazopyrazolones

A catalytic system-controlled divergent reaction strategy was here reported to construct four types of intriguing spiroheterocyclic skeletons from simple and readily available starting materials via a precise chemical bond activation/[n+1] annulation cascade. The tetraazaspiroheterocyclic and trizazspiroheterocyclic scaffolds could be independently constructed by a selective N-N bond activation/[n+1] annulation cascade, a C(sp² )-H activation/[4+1] annulation and a novel tandem C(sp² )-H/C(sp³ )-H bond activation/[4+1] annulation strategy, along with a broad scope of substrates, moderate to excellent yields and valuable transformations. More importantly, in these transformations, we are the first time to capture a N-N bond activation and a C(sp³ )-H bond activation of pyrazolidinones under different catalytic system.

Catalytic asymmetric synthesis of spirocyclobutyl oxindoles and beyond via [2+2] cycloaddition and sequential transformations

Efficient asymmetric synthesis of a collection of small molecules with structural diversity is highly important to drug discovery. Herein, three distinct types of chiral cyclic compounds were accessible by enantioselective catalysis and sequential transformations. Highly regio- and enantioselective [2+2] cycloaddition of (E)-alkenyloxindoles with the internal C[double bond, length as m-dash]C bond of N-allenamides was achieved with N,N'-dioxide/Ni(OTf)₂ as the catalyst. Various optically active spirocyclobutyl oxindole derivatives were obtained under mild conditions. Moreover, formal [4+2] cycloaddition products occurring at the terminal C[double bond, length as m-dash]C bond of N-allenamides, dihydropyran-fused indoles, were afforded by a stereospecific sequential transformation with the assistance of a catalytic amount of Cu(OTf)₂. In contrast, performing the conversion under air led to the formation of γ-lactones via the water-involved deprotection and rearrangement process. Experimental studies and DFT calculations were performed to probe the reaction mechanism.

Rigid 3D-spiro chromanone as a crux for efficient antimicrobial agents: synthesis, biological and computational evaluation

The development of new and effective antimicrobial agents with novel chemical skeletons and working mechanisms is highly desirable due to the increased number of resistant microbes. Different new compounds based upon a 3D-spiro chromanone scaffold such as Mannich bases 2 and 3 in addition to azo dye 4 were synthesized. Besides, the condensation reactions of the hydrazide-spiro chromanone 8 with different ketonic reagents led to the synthesis of pyrazoles (9 & 10) and anils (11 & 13). Moreover, the methoxyl substituted spiro chromanone 14 was condensed with different hydrazines and hydrazides to give the corresponding hydrazones 15-18 in up to 85% yields. The condensation of the hydrazone 18 with salicylaldehyde yielded coumarinyl spiro chromanone 19 in an excellent yield, whereas its reaction with benzaldehyde followed by hydrazine afforded aminopyrazole derivative 21 in 82% yield. The antimicrobial evaluation suggested that hydrazide 8 has a substantial activity against different microbes (S. aureus: D = 22 mm, MIC = 1.64 μM; E. coli: D = 19 mm, MIC = 1.64 μM; C. albicans: D = 20 mm, MIC = 6.57 μM). Moreover, promising antimicrobial activities were observed for azo dye 4 (D = 13-19 mm, MIC = 5.95-11.89 μM), hydrazone 17 (D = 17-23 mm, MIC = 1.88-3.75 μM), and aminopyrazole 21 (D = 14-19 mm, MIC = 2.24-8.98 μM). The molecular docking revealed that compounds 4, 8, 17, and 21 had good to high binding affinities with different microbial targets such as penicillin-binding proteins (-7.4 to -9.9 kcal), DNA gyrase (-7.8 to -9.0 kcal), lanosterol 14-alpha demethylase (-8.2 to -11.2 kcal), and exo-beta-1,3-glucanase (-8.2 to -11.9 kcal). The QSAR analysis ascertained a good correlation between the antimicrobial activity of 3D-spiro chromanone derivatives and their structural and/or physicochemical parameters.