A novel complexity-to-diversity strategy for the diversity-oriented synthesis of structurally diverse and complex macrocycles from quinine

Article abstract of DOI:10.1016/j.bmc.2017.02.060

Recent years have witnessed a global decline in the productivity and advancement of the pharmaceutical industry. A major contributing factor to this is the downturn in drug discovery successes. This can be attributed to the lack of structural (particularly scaffold) diversity and structural complexity exhibited by current small molecule screening collections. Macrocycles have been shown to exhibit a diverse range of biological properties, with over 100 natural product-derived examples currently marketed as FDA-approved drugs. Despite this, synthetic macrocycles are widely considered to be a poorly explored structural class within drug discovery, which can be attributed to their synthetic intractability. Herein we describe a novel complexity-to-diversity strategy for the diversity-oriented synthesis of novel, structurally complex and diverse macrocyclic scaffolds from natural product starting materials. This approach exploits the inherent structural (including functional) and stereochemical complexity of natural products in order to rapidly generate diversity and complexity. Readily-accessible natural product-derived intermediates serve as structural templates which can be divergently functionalized with different building blocks to generate a diverse range of acyclic precursors. Subsequent macrocyclisation then furnishes compounds that are each based around a distinct molecular scaffold. Thus, high levels of library scaffold diversity can be rapidly achieved. In this proof-of-concept study, the natural product quinine was used as the foundation for library synthesis, and six novel structurally diverse, highly complex and functionalized macrocycles were generated.

Full text of DOI:10.1016/j.bmc.2017.02.060

Accepted Manuscript
A novel complexity-to-diversity strategy for the diversity-oriented synthesis of
structurally diverse and complex macrocycles from quinine
J.J. Ciardiello, H.L. Stewart, H.F. Sore, W.R.J.D. Galloway, D.R. Spring
PII:
S0968-0896(17)30147-5
DOI:
http://dx.doi.org/10.1016/j.bmc.2017.02.060
BMC 13590
Reference:
Bioorganic & Medicinal Chemistry
To appear in:
Received Date:
Accepted Date:
23 January 2017
26 February 2017
Please cite this article as: Ciardiello, J.J., Stewart, H.L., Sore, H.F., Galloway, W.R.J.D., Spring, D.R., A novel
complexity-to-diversity strategy for the diversity-oriented synthesis of structurally diverse and complex macrocycles
from quinine, Bioorganic & Medicinal Chemistry (2017), doi: http://dx.doi.org/10.1016/j.bmc.2017.02.060
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Title
A novel complexity-to-diversity strategy for the diversity-oriented synthesis of
structurally diverse and complex macrocycles from quinine
Authors
J. J. Ciardiello, H. L. Stewart, H. F. Sore, W. R. J. D. Galloway, D. R. Spring*
* = corresponding author
spring@ch.cam.ac.uk
Department of Chemistry
The University of Cambridge
Lensfield Road
Cambridge
CB2 1EW
Abstract
Recent years have witnessed a global decline in the productivity and advancement of the
pharmaceutical industry. A major contributing factor to this is the downturn in drug
discovery successes. This can be attributed to the lack of structural (particularly scaffold)
diversity and structural complexity exhibited by current small molecule screening
collections.
Macrocycles have been shown to exhibit a diverse range of biological properties, with
over 100 natural product-derived examples currently marketed as FDA-approved drugs.
Despite this, synthetic macrocycles are widely considered to be a poorly explored
structural class within drug discovery, which can be attributed to their synthetic
intractability.
Herein we describe a novel complexity-to-diversity strategy for the diversity-oriented
synthesis of novel, structurally complex and diverse macrocyclic scaffolds from natural
product starting materials. This approach exploits the inherent structural (including
functional) and stereochemical complexity of natural products in order to rapidly generate
diversity and complexity. Readily-accessible natural product-derived intermediates serve
as structural templates which can be divergently functionalized with different building
blocks to generate a diverse range of acyclic precursors. Subsequent macrocyclisation
then furnishes compounds that are each based around a distinct molecular scaffold.
Thus, high levels of library scaffold diversity can be rapidly achieved. In this proof-of-
concept study, the natural product quinine was used as the foundation for library
synthesis, and six novel structurally diverse, highly complex and functionalized
macrocycles were generated.

Graphical Abstract
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Abbreviations
ADMET, adsorption, distribution, metabolism, excretion and toxicity; CtD, complexity-to-
diversity; DCC, N,N’-dicyclohexylcarbodiimide; DCE, 1,2-dichloroethane; DIPEA, N,N’-
diisopropylethylamine; DMAP, 4-dimethylaminopyridine; DMF, N,N’-dimethylformamide;
DMSO, dimethyl sulfoxide; DOS, diversity-oriented synthesis; EDC, 1-ethyl-3-(3-
dimethylaminopropyl)carbodiimine; FDA, US food and drugs administrations; HATU, 1-
[Bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium
3-oxid
hexafluorophosphate; HTS, high-throughput screening; NCE, new chemical entities; PMI,
principal moments of inertia; PPI, protein-protein interaction; PTSA, para-toluene sulfonic
acid; TEA, triethylamine; THF, tetrahydrofuran.
Keywords
Natural products; macrocycles; diversity-oriented synthesis; complexity-to-diversity;
library synthesis; scaffold; chemical space
1 Introduction
1.1 History
In the 1990s, with the advent of high-throughput screening and combinatorial chemistry,
the drug discovery industry moved towards the rapid and efficient synthesis of large
collections of compounds.1 It was hoped that by screening thousands (and even millions)
of compounds, multiple novel therapeutic leads would be identified. Unfortunately, this
expected surge in productivity did not materialise.2 This disappointing degree of
productivity has been primarily attributed to the relative lack of structural diversity within
the libraries.
Typically, such libraries were comprised of flat, sp2 rich and structurally similar
compounds.2-4 As a result, there has been a drive in recent years to develop robust
methodologies that allow for the rapid generation of compounds possessing more
complex and diverse sp3-rich architectures.
1.2 Natural Products
Natural products represent a highly diverse and structurally innovative compound class.
They possess significant sp3 character, chirality, diverse core scaffolds, differing ratios of
hetero to non-hetero atoms and, computationally, occupy a larger fraction of chemical

space than typical combinatorial libraries.5-8 As such, natural products play a crucial role
in the discovery of drugs. Despite the number of new chemical entities (NCEs) having
fallen in recent years, the number of natural product and natural product-derived NCEs
has remained relatively high; they are responsible for approximately 33% of all small
molecule drugs approved from 1981 to 2014.5,9-17
Despite their key role in drug development, natural products are underrepresented in
compound screening collections. This is attributed to the challenges associated with their
identification, isolation and synthesis. In recent years, a variety of strategies have been
reported to tackle this issue and deliver libraries of natural product-like compounds,
including utilisation of simplified core motifs, diverted total synthesis18,19 and diversity-
oriented synthesis (DOS).5,7,20-28 However, whilst natural products and their derivatives
have featured as the end-goal in many drug discovery programs (both DOS-focused and
otherwise), their use as starting materials in the manufacture of compound libraries
remains relatively rare. Recent years have witnessed a growing interest in the
development of strategies for the synthesis of complex and diverse compounds from
natural products.29-31
One such approach pioneered by Hergenrother and co-workers, is referred to as
“complexity-to-diversity (CtD)”; this involves the production of complex natural product-
like libraries via the controlled application of ring distortion reactions on readily available
natural products.12,21,30-36 The CtD approach, which was inspired by nature’s proclivity to
manufacture complex natural products from common intermediates, enables natural
products which are already inherently structurally complex, to be rapidly converted into
markedly different core scaffolds. The CtD strategy has been successfully applied to
several readily available natural products, including gibberellic acid, adrenosterone,
quinine, abietic acid and fumagillol.21,30-32
1.3 Macrocycles
Macrocycles (compounds containing a ring size of 12 atoms or more) have been shown
to exhibit a diverse range of biological activities and feature in a variety of marketed
drugs.37-39 More specifically, natural-product derived macrocycles, of which over 100 are
found as FDA-approved drugs, have demonstrated excellent efficacy as antibiotics and
anticancer drugs.40-45 They have been shown to exhibit good physiochemical and
pharmacokinetic properties, binding with high affinity and selectivity to targets.42,46
Macrocycles possess unique structural properties that separate them from their acyclic
small molecule counterparts and to which much of their useful biological activity is
attributed. In particular, their potency is credited to their structural pre-organisation and
ability to interact with multiple binding sites across a large area.46 In addition, acyclic
compounds suffer major entropic loss upon binding to proteins due to the restriction of
their conformational degrees-of-freedom. This effect is less prominent during macrocycle
binding, due to a higher level of pre-organisation.44,47-49 Even with a restricted number of
conformations, macrocycles still possess sufficient flexibility to allow them to mould to a
protein surface.42,50 As such, they represent excellent synthetic targets and show great
potential in succeeding where small molecules have previously failed, especially in the
modulation of PPIs.51,52
Their lack of compliance with Lipinski’s “rule of five” bears some of the responsibility for
the slow uptake of macrocycles in medicinal chemistry and HTS campaigns.44
Furthermore their perceived synthetic intractability alongside a lack of understanding of
their ADMET properties has led to concern over their suitability as pharmaceutical
leads.50 Despite the advantages illustrated above, macrocyclic compounds are severely
under-represented and under-exploited within the drug discovery industry.42 As of 2008,
almost half of all new small molecule drugs are generated synthetically whilst almost all
of their macrocyclic counterparts are derived from natural products with minimal

decoration to their structures.46 As such, there is an unmet need for a robust
methodology for the production of structurally diverse macrocycles.
1.4 Summary
Herein, we report the development of a novel complexity-to-diversity (CtD) approach for
the synthesis of libraries of novel, structurally complex and diverse macrocyclic scaffolds
from natural product starting materials (Scheme 1). This approach exploits the inherent
structural and stereochemical complexity in natural products in order to rapidly generate
diversity and complexity through the use of simple chemistry. In this proof-of-concept
study, the natural product quinine was used as the foundation for the library synthesis
and six novel, structurally diverse, highly complex and functionalised macrocycles were
generated.
Scheme 1: Schematic outline of the CtD approach towards macrocycles from natural
product starting materials. Readily accessible natural products are converted into
functionalised intermediates (stage 1) which serve as structural templates that can be
divergently functionalised with different building blocks to generate a diverse range of
acyclic precursors (stage 2). Subsequent macrocyclisation then furnishes compounds
that are each based around a distinct molecular scaffold (stage 3). In addition, the natural
product starting material itself could act as a template for macrocycle construction (i.e.
direct functionalisation of the natural product with suitable building blocks followed by
macrocyclisation).
2 Results and Discussion
2.1 Aims
We considered that the natural product starting materials to be used in the CtD strategy
should ideally be inexpensive, readily available, structurally interesting and feature a
selection of chemically distinct functional groups that would act as handles for
diversification. Based upon these criteria, we selected the alkaloid quinine for initial proof-
of-concept studies. Furthermore, its historical use as an antimalarial drug suggests that
its inherent complexity is sufficient to achieve biological selectivity, and with its two
discrete quinoline and quinuclidine cage ring systems, quinine possesses excellent
structural complexity.

2.2 Strategy
Of the variety of known synthetic transformations of quinine,30,53-60 we identified two key
conversions that would help in demonstrating our strategy.
Firstly, work carried out by Huigens III et al.30 demonstrated the successful Hoffmann
degradation of quinine into quinotoxine- a promising transformation for this project. Not
only would it yield a much more synthetically amenable secondary amine, but it would
furnish another structural template for macrocycle construction.30 Secondly, work by
Zhang et al.55 illustrated a successful thio-ene reaction upon quinine, allowing a facile
means for functionalisation of the pendant alkene.55
Construction of these two additional core templates began with the boiling of quinine (1)
in an aqueous acetic acid solution, which promoted acid-catalysed degradation to afford
o
quinotoxine 2. To form the final core scaffold, quinine (1) was heated overnight at 80 C
in neat mercaptoethanol to deliver diol 3 (Scheme 2).
Scheme 2: Synthesis of quinotoxine 2 and diol 3 from quinine 1. The yield for 2 is the
crude yield, since this was sufficiently pure.
With these three core templates in hand, we anticipated that we could construct three
different structural types of macrocycle (Scheme 3a). It was hoped that the first class of
macrocycles (Mac1) could be constructed by esterifying general building blocks 4 to the
pendant hydroxyl of quinine (1) to afford linear precursors of the form 5. Subsequent
treatment with Grubbs’ II catalyst would then initiate ring-closing metathesis to yield
scaffolds of the form Mac1.
Starting in a similar manner, the second class of macrocycles (Mac2) would begin with
the chemoselective esterification of building blocks 6 to diol 3, followed by the coupling of
building blocks 8 to the secondary alcohol to generate linear precursors 9 (Scheme 3b).
These azido-alkyne intermediates would then undergo copper-mediated click-type 1,3-
dipolar cycloadditions to afford macrocyclic scaffolds of the form Mac2 .
Finally, it was envisaged that we could deliver macrocycles of structural form Mac3 by a
two-step sequence from quinotoxine 2 (Scheme 3c). Initially, quinotoxine 2 would be
treated with a selection of acids 10 to construct amides 11. Exposure of these amides to
the appropriate cyclisation conditions for olefin metathesis, it was hoped, would promote
formation of the desired macrocycles (Mac3).

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Scheme 3: General strategies for the synthesis of macrocycles Mac1, Mac2 and Mac3
from the natural product core, quinine (1).
To test the hypothesis suggested above, we proposed to construct six macrocyclic
scaffolds, two based on each structural class (Scheme 4). However, the modular nature
of this strategy provides the opportunity for substituting both the building blocks and the
natural product core. Thus there is great scope for expanding the breadth of chemical
space interrogated by these diverse libraries.

Scheme 4: Proof-of-concept target macrocycles based on the three macrocyclic
structural classes, Mac1, Mac2 and Mac3
2.3 Building Blocks
Whilst some building blocks were commercially available, others required a short
sequence of steps to synthesise.
Formation of acid 18 was achieved in a four-step sequence from commercially available
ethyl glycinate hydrochloride 19 and 3-hydroxybenzaldehyde. The sequence was
initiated by the alkylation of 3-hydroxybenzaldehyde with allyl bromide to yield ether 22.
Subsequent reductive amination with the hydrochloride 19 furnished amine 23.61 2-
Thiopheneacetic acid was treated with oxalyl chloride and catalytic DMF to generate the
corresponding acid chloride. The freshly prepared acid chloride was quenched with
amine 23 to deliver amide 24. Saponification of the amide with LiOH afforded the desired
acid 18 (Scheme 5).

Scheme 5: Synthesis of building block 18
Treatment of methyl 5-(chloromethyl)-2-furoate 25 with NaN3, in line with the procedure
detailed by Beckmann et al.,62 afforded azido compound 26, after which a subsequent
LiOH- mediated saponification furnished the desired carboxylic acid 27 (Scheme 6).62
Scheme 6: Synthesis of building block 27
We hoped to furnish acid 28 in a three-step sequence from readily available methyl
bromoacetate 29. Exposure of the methyl ester 29 to propargylamine and TEA yielded
amine 30. Treatment of 4-bromophenylacetic acid with oxalyl chloride generated the
corresponding acid chloride, which was subsequently quenched with amine 30 to deliver
amide 31. LiOH mediated hydrolysis conditions furnished the desired building block acid
28. Following the protocol outlined by Beckmann et al.,62 treatment of benzyl chloride 32
with NaN3 in DMSO successfully delivered the second building block acid 33 (Scheme 7).
Scheme 7: Synthesis of building blocks 28 and 33
2.4 Macrocycles of the structural class Mac1
It was anticipated that macrocycles 12 and 13 could be constructed in two steps from
quinine (1). Synthesis began with the DCC-mediated esterification of quinine (1) with
acids 18 and 34 to furnish linear precursors 35 and 36 respectively. Subsequent
treatment of these intermediates with the Grubbs II catalyst afforded macrocycles 12 and

13 (Scheme 8). Whilst it was not possible to determine the stereochemistry of the
resulting alkene in macrocycle 12, the alkene in macrocycle 13 was determined to have
cis geometry from two-dimensional NMR data.
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Scheme 8: Synthesis of macrocycles 12 and 13
2.5 Macrocycles of the structural class Mac2
It was envisaged that macrocycles 14 and 15 could be furnished in a three-step
sequence from diol 3 (Scheme 9). Synthesis began with the coupling of acids onto the
primary hydroxyl of compound 3. EDC-mediated esterification of the core compound with
acid 33 afforded intermediate 38, whilst the same conditions effected intermediate 39
from 4-pentynoic acid 37.
Subsequently, we attempted the esterification of 38 with acid 28 to afford linear precursor
40. Whilst LCMS data indicated formation of 40 in the reaction mixture, it was not
possible to obtain a spectroscopically pure sample before the material completely
degraded. So the material was carried through without purification. The furnishing of
linear precursor 41 was achieved by the DCC-mediated esterification of intermediate 39
with acid 27. Treatment of both linear precursors with CuI promoted the desired click
cycloaddition step and afforded macrocycles 15 and 14, respectively (Scheme 9).

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Scheme 9: Synthesis of macrocycles 14 and 15
2.6 Macrocycles of the structural class Mac3
Macrocycles 16 and 17 were synthesized via a two-step sequences from quinotoxine.
Synthesis began with HATU-mediated amide coupling of quinotoxine 2 and the acids 8-
nonenoic acid and undecylenic acid to furnish linear precursors 42 and 43 respectively.
Exposure of these alkene-containing intermediates to Grubbs II triggered ring-closing
metathesis and delivered two macrocyclic scaffolds: 16 and 17 respectively (Scheme 10).
Both macrocycles were isolated as single isomers but in both cases the double bond
geometry could not be determined.

Scheme 10: Synthesis of macrocycles 16 and 17
Molecular Shape Analysis
It has been argued that the overall molecular shape diversity of a compound library is
the most fundamental indicator of overall biological (functional) diversity.63,64 To
assess the 3D shape diversity of the six macrocycles, we carried out a principal
moments of inertia (PMI) analysis. PMI plots are often used to visually represent the
shape diversity of compounds of a collection in “molecular shape space” spanned by
the three basic extreme shape types: “rod-like” (e.g., acetylene), “disk-like” (e.g.,
benzene) and “spherical” (e.g., adamantine). After an initial conformational search
and energy minimisation on the DOS library, we selected the lowest energy
conformations for each compound and calculated their principal moments of inertia
(full details of the PMI analysis can be found in Section 4.3). We also computed the
PMIs for 40 top-selling drugs, 60 natural products and 36 macrocycles in clinical
development so that we could compare the shape diversity between these
collections and our library. The PMI plot produced is shown below (Figure 1a).
a)
b)
Figure 1: a) Principal moments of inertia plot illustrating the shape diversity of our proof-
of-concept library, including both cis (c) and trans (t) isomers for the macrocycles for
which the alkene geometry could not be determined, and 3 reference sets. The red
marks represent our collection, with the orange marker highlighting the position of
quinine. b) PMI plot for Isidro Llobet’s library.44,62
The collection of 40 top-selling drugs are mainly one- and two- dimensional, with very
little three-dimensionality observed. In contrast, the natural product, macrocyclic
compound collection and our proof-of-concept library demonstrate much more three
dimensional “spherical” character. It is pleasing to see that our small proof-of-concept
library mimics the shape diversity of the natural product and macrocycle collections.
Furthermore, we have included on the plot the natural product core, quinine, to
demonstrate the breadth of shape diversity generated from a single compound. Taking
this further, if we compare our PMI plot to a similar one constructed to assess Isidro-
Llobet’s macrocycle library47,65 (against the same reference set), we can see that both
DOS libraries exhibit similar levels of shape diversity (Figure 1b). This result is
particularly pleasing, given that our collection is significantly smaller.
Conclusions
Herein we have reported a complexity-to-diversity (CtD) strategy for the diversity-oriented

synthesis of structurally complex and diverse macrocycles from natural product starting
materials. In this proof-of-concept study, quinine was used as the foundation for library
synthesis and six novel, structurally diverse, highly complex and functionalised
macrocycles were generated, each of which is based around a distinct molecular
scaffold.
Our library showed excellent shape diversity in the PMI analysis, rivaling that of the
natural product and macrocycles in clinical development reference sets. It also shows
excellent shape diversity compared to a diverse macrocyclic library over thirty times its
size. In principle, a wider range of building blocks could be employed in the routes
described above in order to access additional macrocyclic compounds from quinine. This
modular nature of the strategy should allow for easy substitution of building blocks and
possibility or localised SAR studies upon hit identification. It is anticipated that our
general CtD approach will prove applicable to a wider range of natural products and
therefore represent a useful strategic method for the synthesis of complex and diverse
macrocyclic scaffolds.
4 Materials and Methods
4.1 General Experimental
All non-aqueous reactions were performed in dry glassware under an atmosphere of N2
using anhydrous solvents. Tetrahydrofuran was dried over sodium wire and distilled from
a mixture of lithium aluminium hydride and calcium hydride with triphenyl methane as the
indicator. CH2Cl2, toluene, methanol and acetonitrile were distilled from calcium hydride.
Chemicals were purchased from commercial sources and used as received unless
otherwise stated. Reactions were carried out at room temperature unless otherwise
o
stated. Reactions at 0 C were maintained using an ice/water bath and reactions at -78
oC were maintained using an acetone/dry ice bath.
Thin layer chromatography, used to analyse and monitor reaction progress, was carried
out on Merck Kieselgel 60 F254 plates with visualisation by UV fluorescence (λmax = 254
nm) or by staining with potassium permanganate. Rf values are quoted to the nearest
0.01. Flash column chromatography was performed using slurry-packed SiO2 (Merck
Grade 9385, 230-400 mesh) under positive pressure of compressed air. Automated
chromatography was carried out using a Teledyne ISCO Combiflash® chromatography
system.
Preparative HPLC purification was performed on an Agilent 1260 Infinity system fitted
with a Supelcosil ABZ+Plus column (250 mm x 21.2 mm, 5 µm) using linear gradient
systems (solvent A: 0.1% (v/v) TFA in water, solvent B: 0.05% (v/v) TFA in acetonitrile) at
a flow rate of 20 mL min-1.
Analytical HPLC analysis was performed on an Agilent 1260 Infinity system fitted with a
Supelcosil ABZ+Plus column (150 mm x 4.6 mm, 3 µm) using linear gradient systems
(solvent A: 0.05% (v/v) TFA in water, solvent B: 0.05% (v/v) TFA in acetonitrile) over 15
min at a flow rate of 1 mL min-1. Retention times (tr) are reported to the nearest 0.01 min.
Infrared spectra were recorded on a Perkin Elmer Spectrum One FT-IR spectrometer.
Absorption maxima (νmax) are quoted in wavenumbers (cm-1) and assigned as either:
weak (w), medium (m), strong (s) or broad (br).
Melting points were obtained on a Buchi B-545 melting point apparatus and are
uncorrected.
ͦͤ
Optical rotations were recorded on an Anton-Paar MCP polarimeter.
values are
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reported in 10-1 deg cm2 g-1 at 598 nm, concentration (c) is given in g(100 mL)-1.

Proton nuclear magnetic resonance (1H NMR) were recorded on the following
instruments: Bruker DPX-400 (400 MHz), Bruker Avance 400 QNP (400 MHz), Bruker BB
500 (500 MHz) and Bruker Avance 500 Cryo Ultrashield (500 MHz). They were recorded
at room temperature unless otherwise stated. Chemical shifts are referenced to the
residual non-deuterated solvent peak and quoted in parts per million to the nearest 0.01.
Coupling constants are quoted in Hertz to the nearest 0.1 Hz and the data is reported as
follows: chemical shift, integration, multiplicity (s, singlet; d, doublet; t, triplet; dd, doublet
of doublets; m, multiplet; br, broad), coupling constant(s) and assignment. Assignments
are supported by either chemical shift, coupling constants, 2D experiments (COSY,
HMQC, HMBC and NOESY) or by comparison with similar, fully characterised
compounds.
Carbon nuclear magnetic resonance (13C NMR) were recorded on the following
instruments: Bruker DPX-400 (101 MHz), Bruker Avance 400 QNP (101 MHz), Bruker BB
500 (126 MHz) and Bruker Avance 500 Cryo Ultrashield (126 MHz). Chemical shifts are
referenced to the residual non-deuterated solvent peak and quoted in parts per million to
the nearest 0.1 ppm. Assignments are supported by either chemical shift, APT/DEPT, 2D
experiments (HMQC and HMBC) or by comparison with similar, fully characterised
compounds.
The numbering of molecules used for 13C and 1H NMR assignments does not conform to
IUPAC standards.
Diastereotopic protons are identified as Hxa and Hxb (or Cxa and Cxb) where “x” is the
numerical assignment and Hxa represents the higher shift. Terminal alkene protons are
identified as
Hxc and Hxt where “x” is the numerical assignment, “c” indicates a cis coupling constant
has been observed and “t” indicates a trans coupling constant has been observed.
Low-resolution mass spectra (ESI) were recorded using an LCMS system (Agilent 1200
series LC with an ESCi Multi-Mode IonizationWaters ZQ spectrometer using MassLynx
4.0 software).
High-resolution mass spectrometry (HRMS) was carried out on a Micromass LCT
Premier spectrometer using electron spray ionisation (ESI) or electron impact (EI)
techniques. Masses are quoted within the 5ppm error limit.
4.2 Methods
4.2.1 Cores
4.2.1.1 Quinotoxine (2)
Quinine (20.0 g, 61.6 mmol) was dissolved in H2O (600 mL) and AcOH (50 mL) and
heated at reflux for 118 h. The reaction mixture was quenched with an aqueous NaOH
solution (25% by weight) and extracted with EtOAc (3 x 600 mL). The organic extracts
were combined, washed with H2O (500 mL), brine (400 mL) and dried (MgSO4). The
solution was filtered and the solvent removed under reduced pressure to yield the title

compound as a crude brown oil, which was used without further purification (18.8 g, 57.9
mmol, 94 %).
Rf = 0.30 (10% methanol in CH2Cl2, TEA-deactivated SiO2).
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ë = -17.8 (c = 0.18 in CHCl3).
IR: λmax = 2924 (m, C–H), 1689 (m, C=O), 1617 (s, C=C), 1580 (w, C=C), 1506 (s, C=C).
1H NMR (500 MHz, d6-DMSO): δH = 8.88 (1H, d, J = 4.6 Hz, H5), 8.01 (1H, d, J = 9.2 Hz,
H3), 7.90 (1H, d, J = 4.3 Hz, H6), 7.69 (1H, d, J = 2.8 Hz, H9), 7.48 (1H, dd, J = 9.2, 2.8
Hz, H2), 6.17 – 6.09 (1H, m, H18), 5.11 (1H, dd, J = 17.1, 2.1 Hz, H19t), 5.07 (1H, dd,
10.4, 2.4 Hz, H19c), 3.88 (3H, s, H20), 3.11 (2H, t, J = 7.5 Hz, H11), 2.96 (1H, d, J = 9.8
Hz, H15a), 2.85 (1H, d, J = 10.7 Hz, H16a), 2.74 (1H, d, J = 11.9 Hz, H16b), 2.58 – 2.52
(1H, m, H15b), 2.30 (1H, br s, H17), 1.66 – 1.40 (4H, m, H12, H13, H14a), 1.37 - 1.30
(1H, m, H14b).ꢀ
13C NMR (126 MHz, d6-DMSO): δC = 204.9 (C10), 158.9 (C1), 148.1 (C5), 145.2 (sp2-C),
141.1 (sp2-C), 136.5 (C18), 131.6 (C3), 124.8 (sp2-C), 122.5 (C2), 121.1 (C6), 116.5
(C19), 103.7 (C9), 55.9 (C20), 51.2 (C16), 45.9 (C15), 42.3 (C17), 39.4 (C11), 38.0
(C13), 28.4 (C14), 27.6 (C12).
HRMS (ESI+): m/z found [M+H]+ 325.1916, C20H25O2N2 required 325.1911.
Literature procedure followed.30
4.2.1.2 Diol (3)
A stirred solution of quinine (10.0 g, 30.8 mmol) in 2-mercaptoethanol (30 mL) was
refluxed at 80 oC for 72 h after which the solvent was removed under reduced pressure.
The crude product was purified by flash column chromatography on TEA-deactivated
silica, eluting with a gradient from 0% to 20% MeOH in CH2Cl2 to yield the title compound
as a pale yellow foam (5.30 g, 13.2 mmol, 43%).
Rf = 0.13 (40% EtOAc in petroleum ether 40–60, TEA-deactivated SiO2).
̋̉
ë
= -136 (c = 0.17 in MeOH).
IR: λmax = 3151 (br, O–H), 2913 (w, C–H), 1620 (s, C=C), 1591 (w, C=C), 1506 (s, C=C).
1H NMR (500 MHz, d4-MeOH): δH =8.68 (1H, d, J = 4.6 Hz, H5), 7.97 (1H, d, J = 9.5 Hz,
H3), 7.70 (1H, d, J = 4.6 Hz H6), 7.46 – 7.43 (2H, m, H2, H9), 5.59 (1H, d, J = 3.4 Hz,
H10), 4.00 (3H, s, H20), 3.72 – 3.66 (1H, m, H15a), 3.62 (2H, t, J = 6.7 Hz, H22), 3.17 –
3.11 (2H, m, H11, H16a), 2.75 – 2.68 (1H, m, H15b), 2.58 (2H, t, J = 6.7 Hz, H21), 2.50
(2H, t, J = 7.3 Hz, H19), 2.48 – 2.43 (1H, m, H16b), 1.96 – 1.86 (2H, m, H12a, H14a),
1.80 (2H, br s, H13, H17), 1.58 – 1.42 (4H, m, H12b, H14b, H18).
13C NMR (126 MHz, d4-MeOH): δC = 159.9 (C1), 150.8 (sp2-C), 148.3 (C5), 144.9 (sp2-
C), 131.5 (C3), 128.3 (sp2-C), 123.5 (C2/C9), 120.3 (C6), 102.7 (C2/C9), 72.4 (C10),
62.6 (C22), 61.1 (C11), 59.2 (C16), 56.6 (C20), 44.3 (C15), 35.8 (C18), 35.7 (C17), 35.4
(C21), 31.0 (C19), 28.8 (C14), 27.1 (C13), 21.7 (C12).

HRMS (ESI+): m/z found [M+H]+ 403.2038, C22H31O3N2S required 403.2050.
Literature procedure followed.55
4.2.2 Building Blocks
4.2.2.1 3-(allyloxy)benzaldehyde (22)
To a stirred solution of 3-hydroxybenzaldehyde (8.0 g, 65.6 mmol) in acetonitrile (80 mL)
was added allylbromide (11.0 mL, 131 mmol), KI (1.09 g, 6.56 mmol), 18-crown-6 (864
mg, 3.26 mmol) and K2CO3 (26.4 g, 191 mmol) at rt, after which the solution was refluxed
at 75 oC for 18 h. The K2CO3 was filtered off and the solvent was removed under reduced
pressure. H2O (100 mL) was added and the aqueous layer extracted with EtOAc (2 x 100
mL). The organic layer was separated, washed with brine (50 mL), dried (Na2SO4) and
the solvent removed under reduced pressure to yield the title compound as an orange oil,
which was used without further purification (10.5 g, 64.4 mmol, 98%).
Rf = 0.38 (5% EtOAc in hexane).
IR: λmax = 2861 (w, C–H), 1681 (s, C=O), 1598 (s, C=C), 1483 (m, C=C), 1457 (m, C=C).
1H NMR (400 MHz, CDCl3): δH = 9.92 (1H, s, H10), 7.37 - 7.44 (2H, m, H6 & H7), 7.36
(1H, dd, J=2.0, 1.0 Hz, H9), 7.15 (1H, dt, J=7.2, 2.4 Hz, H5), 5.96 - 6.09 (1H, ddt, J=17.2,
10.5, 5.2 Hz, H2), 5.40 (1H, dq, J=17.3, 1.5 Hz, H1t), 5.28 (1H, dq, J=10.6, 1.4 Hz, H1c),
4.55 (2H, dt, J=5.3, 1.4 Hz, H3)
13C NMR (101 MHz, CDCl3): δC = 192.0 (C10), 159.1 (C4), 137.8 (C8), 132.7 (C2), 130.1
(C6), 123.5 (C7), 122.0 (C5), 118.0 (C1), 113.1 (C9), 68.9 (C3)
HRMS (ESI+): m/z found [M+H]+ 163.0751, C10H11O2 required 163.0754.
Modified from an unpublished procedure.66 Data consistent with that reported in the
literature.67
4.2.2.2 ethyl (3-(allyloxy)benzyl)glycinate (23)
To a stirred solution of 22 (774 mg, 4.77 mmol) and ethyl glycine hydrochloride (1.00 g,
7.16 mmol) in DCE (30 mL), TEA (1.33 mL, 9.54 mmol) and 4Å molecular sieves were
added. After 2 h, 50% of the required NaBH(OAc)3 (1.42 g, 6.68 mmol) was added and
the final 50% added after an additional 20 min. The reaction was allowed to stir at rt for
12 h, after which it was quenched with saturated aqueous Na2CO3 solution (30 mL) and
subsequently extracted with CH2Cl2 (3 x 30 mL). The organic extracts were combined,
washed with brine (50 mL) and dried (MgSO4). The solution was filtered and solvent
removed under reduced pressure. The crude product was purified by flash column
chromatography (CombiFlash Companion), eluting with a gradient from 0% to 100%
EtOAc in petroleum ether 40–60 to yield the title compound as a colourless oil (456 mg,
1.83 mmol, 38%).
Rf =0.16 (40% EtOAc in petroleum ether 40–60).
IR: λmax = 2983 (w, C–H), 1734 (s, C=O), 1598 (m, C=C), 1585 (m, C=C).
1H NMR (500 MHz, CDCl3): δH =7.25 (1H, t, J = 7.9 Hz, H6), 6.95 – 6.92 (2H, m,
H5/H7/H9), 6.85 – 6.82 (1H, m, H5/H7/H9), 6.08 (1H, ddt, J = 17.4, 10.7, 5.2 Hz, H2),

5.44 (1H, dq, J = 17.4, 1.5 Hz, H1t), 5.30 (1H, dq, J = 10.7, 1.2 Hz, H1c) 4.56 (2H, dt, J =
5.5, 1.5 Hz, H3), 3.81 (2H, s, H10/H11), 3.42 (2H, s, H10/H11), 4.22 (2H, q, J = 7.3 Hz,
H13), 1.30 (3H, t, J = 7.3 Hz, H14).
13C NMR (126 MHz, CDCl3): δC = 172.4 (C12), 158.8 (C4), 141.2 (C8), 133.3 (C2), 129.4
(C6), 120.7 (C5/C7/C9), 117.6 (C1), 114.5 (C5/C7/C9), 113.5 (C5/C7/C9), 68.7 (C3),
60.8 (C13), 53.2 (C10), 50.1 (C11), 14.3 (C14).
HRMS (ESI+): m/z found [M+H]+ 250.1434, C14H20O3N required 250.1443.
Modified from a literature procedure.61 Novel compound.
4.2.2.3 Ethyl N-(3-(allyloxy)benzyl)-N-(2-(thiophen-2-yl)acetyl)glycinate (24)
Acyl chloride preparation: To a stirred solution of 2-thiopheneacetic acid (260 mg, 1.83
mmol) and oxalyl chloride (201 µL, 2.38 mmol) in CH2Cl2 (6 mL), catalytic amounts of
DMF were added. After stirring for 5 h until TLC indicated complete turnover, the solvent
was removed under reduced pressure and the acyl chloride was used without further
purification.
Amide formation: To a stirred solution of the freshly prepared acyl chloride in CH2Cl2 (6
mL), 23 (350 mg, 1.40 mmol) and saturated aqueous NaHCO3 (excess) were added.
After vigorous stirring for 18 h, the organic solvent was removed under reduced pressure.
The residue was diluted with EtOAc (20 mL), washed successively with saturated
aqueous NaHCO3 solution (20 mL), aqueous HCl solution (1.0 M, 20 mL), H2O (20 mL)
and brine (20 mL) and dried (MgSO4). The solution was filtered and solvent removed
under reduced pressure. The crude product was purified by flash column
chromatography on silica, eluting with a gradient from 10% to 40% EtOAc in petroleum
ether 40–60 to yield the title compound as a colourless oil (165 mg, 441 µmol, 24%).
Rf = 0.44 (50% EtOAc in petroleum ether 40–60).
IR: λmax = 2982 (w, C–H), 1742 (s, C=O), 1649 (s, C=C), 1601 (m, C=C).
1H NMR (500 MHz, d6-DMSO, 120 oC): δH = 7.41 (1H, dd, J = 5.0, 2.9 Hz, ArH), 7.26 –
7.22 (2H, m, ArH), 7.02 (1H, dd, J = 5.0, 0.8 Hz, ArH), 6.88 – 6.85 (1H, m, ArH), 6.84 –
6.80 (2H, m, ArH), 6.04 (1H, ddt, J = 17.4, 10.5, 5.5 Hz, H2), 5.38 (1H, dq, J = 17.2, 1.8
Hz, H1t), 5.26 (1H, dq, J = 10.7, 1.3 Hz, H1c), 4.60 (2H, br s, H10/H11), 4.55 (2H, dt, J =
5.2, 1.6 Hz, H3), 4.11 (2H, q, J = 7.1 Hz, H13), 4.07 (2H, br s, H10/H11), 3.76 (2H, br s,
H16), 1.20 (3H, t, J = 7.1 Hz, H14).
o
13C NMR (126 MHz, d6-DMSO, 120 C): δC = 171.1 (sp2-C), 135.5 (sp2-C), 134.2 (C2),
129.0, 125.7, 122.6 (sp2-C), 117.4 (C1), 69.0 (C3), 60.5 (C13), 40.7, 34.8 (sp3-C), 14.2
(C14).
Quaternary carbons 4 and 8 were not observed. Due to the rotameric nature of the
amide, carbons 15 - 20 were also not observed.
HRMS (ESI+): m/z found [M+H]+ 374.1429, C20H24O4NS required 374.1421.
Modified from a literature procedure.62
4.2.2.4 Acid (18)

To a stirred solution of 24 (149 mg, 399 µmol) in THF (1 mL) was added an aqueous
LiOH solution (1.0 M, 2 mL). After stirring for 6 h the reaction was acidified to pH 3 with
an aqueous HCl solution (37%) and extracted with Et2O (3 x 30 mL). The organic
extracts were combined, washed with H2O (30 mL), brine (30 mL) and dried (MgSO4)
The solvent was removed under reduced pressure to yield the title compound as a pale
yellow oil, which was used without further purification (122 mg, 353 µmol, 89%).
IR: λmax = 2929 (w, C–H), 1733 (s, C=O), 1647 (s, C=C), 1600 (s, C=C).ꢀ
1H NMR (500 MHz, d6-DMSO, 120 oC): δH = 7.40 (1H, dd, J = 5.0, 3.1 Hz, ArH), 7.25 –
7.22 (2H, m, ArH), 7.03 (1H, dd, J = 4.7, 1.1 Hz, ArH), 6.88 – 6.85 (1H, m, ArH), 6.83 –
6.80 (2H, m, ArH), 6.05 (1H, ddt, J = 17.5, 10.7, 5.3 Hz, H2), 5.39 (1H, dq, J = 17.2, 1.7
Hz, H1t), 5.25 (1H, dq, J = 10.5, 1.5 Hz, H1c), 4.60 (2H, br s, H10/H11/H13), 4.55 (2H,
dt, J = 5.2 Hz, 1.6 Hz, H3), 4.00 (2H, br s, H10/H11/H13), 3.75 (2H, br s, H10/H11/H13).
13C NMR (126 MHz, d6-DMSO, 120 oC): δC = 171.1 (C12), 159.4 (C4), 139.4, 135.8 (C8,
C17), 134.3 (C2), 130.0, 129.2, 125.7, 122.6, 120.5 (sp2-C), 117.5 (C1), 114.7, 114.6
(sp2-C) 69.1 (C3), 34.9 (C). Due to the rotameric nature of the amide, two carbons out of
10, 11 and 16 were not observed. C13 was also not observed.
HRMS (ESI+): m/z found [M+H]+ 346.1106, C18H20O4NS required 346.1108.
4.2.2.5 methyl 5-(azidomethyl)furan-2-carboxylate (26)
A solution of methyl 5-(chloromethyl)-2-furoate (800 mg, 4.60 mmol) and NaN3 (897 mg,
o
13.8 mmol) in DMF (10 mL) was heated at 65 C for 1.5 h. The solution was diluted with
EtOAc (50 mL), washed successively with H2O (40 mL), saturated aqueous LiCl solution
(2 x 40 mL), brine (40 mL) and dried (MgSO4). The solution was filtered and the solvent
removed under reduced pressure to yield the title compound as an orange oil, which was
used without further purification (695 mg, 3.84 mmol, 83%).
Rf = 0.14 (10% EtOAc in petroleum ether 40–60).
IR: λmax = 2957 (m, C–H), 2096 (s, -N3), 1723 (s, C=O), 1597 (w, C=C), 1534 (m, C=C),
1522 (m, C=C).
1H NMR (400 MHz, CDCl3): δH = 7.17 (1H, d, J = 3.4 Hz, H4), 6.49 (1H, d, J= 3.4 Hz,
H5), 4.40 (2H, s, H7), 3.92 (3H, s, H1).
13C NMR (101 MHz, CDCl3): δC = 158.8 (C2), 153.2 (C3/C6), 144.9 (C3/C6), 118.7 (C4),
111.0 (C5), 52.1 (C7), 46.9 (C1).
HRMS (ESI+): m/z found [M+Na]+ 204.0372, C7H7O3N3Na required 204.0380.
Literature procedure followed.68
4.2.2.6 5-(azidomethyl)furan-2-carboxylic acid (27)

To a stirred solution of 26 (650 mg, 3.59 mmol) in THF (17 mL) was added an aqueous
LiOH solution (1.0 M, 17 mL). After stirring for 2 h the reaction was acidified to pH 3 with
an aqueous HCl solution (3.0 M) and the solvent was removed under reduced pressure.
The product was extracted with Et2O (2 x 50 mL). The organic extracts were combined,
washed with H2O (40 mL), brine (40 mL) and dried (MgSO4). The solution was filtered
and the solvent was removed under reduced pressure to yield the title compound as an
amorphous pale yellow solid, which was used without further purification (495 mg, 2.96
mmol, 82%).
IR: λmax = 2856 (br, O–H), 2084 (m, -N3), 1683 (s, C=O), 1596 (m, C=C), 1536 (s, C=C).
1H NMR (400 MHz, CDCl3): δH = 7.33 (1H, d, J = 3.4 Hz, H4), 6.54 (1H, d, J = 3.1 Hz,
H5), 4.44 (2H, s, H7).
13C NMR (101 MHz, CDCl3): δC = 163.1 (C2), 154.5 (C3/C6), 144.0 (C3/C6), 120.9 (C4),
111.3 (C5), 47.0 (C7).
Known compound.62
4.2.2.7 Methyl prop-2-yn-1-ylglycinate (30)
A solution of methyl bromoacetate (3.00 mL, 31.7 mmol), propargylamine (1.35 mL, 21.1
mmol) and TEA (4.42 mL, 31.7 mmol) in acetonitrile (60 mL) was stirred at 50 oC for 23
h. The solution was filtered and the solvent removed under reduced pressure. The crude
product was purified by flash column chromatography on silica, eluting with a gradient
from 10% to 40% EtOAc in petroleum ether 40–60 to yield the title compound as an
orange oil (1.87 g, 14.7 mmol, 46%).
Rf = 0.12 (50% EtOAc in petroleum ether 40–60).
IR: λmax = 3284 (w, C–H), 2956 (w, C–H), 1735 (s, C=O).
1H NMR (500 MHz, CDCl3): δH = 3.76 (3H, s, H1), 3.54 (2H, s, H3), 3.51 (2H, d, J = 2.4
Hz, H4), 2.25 (1H, t, J = 2.4 Hz, H6).
13C NMR (126 MHz, CDCl3): δC = 172.3 (C2), 81.1 (C5), 72.0 (C6), 51.9 (C1), 49.1 (C3),
37.7 (C4).
HRMS (ESI+): m/z found [M+H]+ 128.0709, C6H10O2N required 128.0706.
Literature procedure followed.69 Data consistent with that reported in the literature.69
4.2.2.8 Methyl N-(2-(4-bromophenyl)acetyl)-N-(prop-2-yn-1-yl)glycinate (31)
Acyl chloride preparation: To a stirred solution of 4-bromophenylacetic acid (1.10 g, 5.12
mmol) and oxalyl chloride (565 µL, 6.68 mmol) in CH2Cl2 (15 mL), catalytic amounts of
DMF were added. After stirring for 8 h until TLC indicated complete turnover, the solvent

was removed under reduced pressure and the acyl chloride was used without further
purification.
Amide formation: To a stirred solution of the freshly prepared acyl chloride in CH2Cl2 (15
mL), 30 (500 mg, 3.93 mmol) and saturated aqueous NaHCO3 solution (excess) were
added. After vigorous stirring for 15 h, the layers were separated and the organic phase
was washed successively with aqueous HCl solution (1.0 M, 20 mL), saturated aqueous
NaHCO3 solution (20 mL), H2O (20 mL), brine (20 mL) and dried (MgSO4). The solution
was filtered and solvent removed under reduced pressure. The crude product was
purified by flash column chromatography on silica, eluting with a gradient from 10% to
50% EtOAc in petroleum ether 40–60 to yield the title compound as a colourless oil (901
mg, 2.78 mmol, 71%).
Rf = 0.30 (50% EtOAc in petroleum ether 40–60).
IR: λmax = 3290 (w, C–H), 2953 (w, C–H), 1743 (s, C=O), 1652 (s, C=O).
1H NMR (500 MHz, d6-DMSO, 120 oC): δH = 7.48 (2H, d, J = 8.4 Hz, H11), 7.21 (2H, d, J
= 8.4 Hz, H10), 4.30 – 4.21 (4H, m, H3, H4), 3.76 (2H, br s, H8), 3.68 (3H, s, H1), 3.02
(1H, br s, H6).
o
13C NMR (126 MHz, d6-DMSO, 120 C): δC = 170.6, 169.6 (C2, C7), 135.1 (sp2-C),
131.9, 131.4 (C10, C11), 120.2 (sp2-C), 79.2 (C2/C5), 52.0 (C1), 38.9 (sp3-C). Due to the
rotameric effects of the amide, carbons 5/6 and 2 from 3/4/8 were not observed.
HRMS (ESI+): m/z found [M+H]+ 324.0225, C14H15O3N79Br required 324.0230.
Modified from a literature procedure.62
4.2.2.9 N-(2-(4-bromophenyl)acetyl)-N-(prop-2-yn-1-yl)glycine (28)
To a stirred solution of 31 (865 mg, 2.67 mmol) in THF (13 mL) was added an aqueous
LiOH solution (1.0 M, 13 mL). After stirring for 21 h the reaction was acidified to pH 3 with
an aqueous HCl solution (3.0 M) and the solvent was removed under reduced pressure.
The product was extracted with Et2O (2 x 20 mL). The organic extracts were combined,
washed with H2O (30 mL), brine (30 mL) and dried (MgSO4). The solvent was removed
under reduced pressure to yield the title compound as an amorphous white solid, which
was used without further purification (691 mg, 2.23 mmol, 83%).
IR: λmax = 3260 (w, C–H), 2929 (br, O–H), 1744 (s, C=O), 1608 (s, C=C).
1H NMR (500 MHz, d6-DMSO, 120 oC): δH = 7.46 (2H, d, J = 8.1 Hz, H11), 7.21 (2H, d, J
= 7.8 Hz, H10), 4.26 (2H, br s, H3/H4), 4.17 (2H, br s, H3/H4), 3.74 (2H, br s, H8), 3.01
(1H, br s, H6).
o
13C NMR (126 MHz, d6-DMSO, 120 C): δC = 170.7, 170.3 (C2, C7), 135.2 (sp2-C),
131.9, 131.4 (C10, C11), 120.1 (sp2-C), 79.5, 75.1 (C5, C6), 48.3, 38.9 (sp3-C). One sp3
carbon missing.ꢀ
HRMS (ESI+): m/z found [M+Na]+ 331.9897, C13H12O3N79BrNa required 331.9893.
4.2.2.10 3-(azidomethyl)benzoic acid (33)

A stirred solution of 3-(chloromethyl)benzoic acid (1.50 g, 8.79 mmol) and NaN3 (686 mg,
10.6 mmol) in DMSO was stirred at 30 oC for 1.5 h. The reaction mixture was diluted with
EtOAc (50 mL), washed successively with H2O (2 x 30 mL), brine (30 mL) and dried
(MgSO4). The solution was filtered and the solvent removed under reduced pressure to
yield the title compound as an off-white crystalline solid, which was used without further
purification (1.10 g, 6.21 mmol, 71%).
m.p. =72–74 oC.
IR: λmax = 2740 (br, O–H), 2087 (s, -N3), 1678 (s, C=O), 1607 (w, C=C), 1587 (w, C=C).
1H NMR (400 MHz, CDCl3): δH = 8.13 (1H, d, J = 7.8 Hz, H5/H7), 8.11 (1H, s, H3), 7.62
(1H, d, J = 7.5 Hz, H5/H7), 7.55 (1H, t, J = 7.7 Hz, H6), 4.47 (2H, s, H8).
13C NMR (101 MHz, CDCl3): δC = 171.6 (C1), 136.1 (C2/C4), 133.4 (C3/C5/C6/C7),
130.1 (C3/C5/C6/C7), 129.9 (C2/C4), 129.8 (C3/C5/C6/C7), 129.2 (C3/C5/C6/C7), 54.3
(C8).
HRMS (ESI+): m/z found [M-H]– 176.0457, C8H6O2N3 required 176.0465.
Literature procedure followed.62 Data consistent with that reported in the literature.62
4.2.3 Macrocycles from structural class Mac1
4.2.3.1 Ester (35)
A solution of quinine (43.8 mg, 135 µmol), 18 (46.6 mg, 135 µmol) and DMAP (1.70 mg,
o
13.5 µmol) in CH2Cl2 (0.5 mL) was cooled to 0 C, after which a solution of DCC (30.7
mg, 149 µmol) in CH2Cl2 (0.5 mL) was added. The solution was stirred at rt for 21 h, after
which an additional 0.5 eq. of DCC was added. Stirring was allowed to continue at rt for
27 h. The reaction mixture was diluted with CH2Cl2 (10 mL) and washed successively
with saturated aqueous NaHCO3 solution (2 x 20 mL), H2O (20 mL), brine (20 mL) and
dried (MgSO4). The solution was filtered and the solvent removed under reduced
pressure. The crude product was purified by flash column chromatography on silica,
eluting with a gradient from 0% to 4% methanol in EtOAc with 1% TEA to yield the title
compound as an amorphous pale yellow solid (40.4 mg, 62.0 µmol, 46%).
Rf = 0.37 (10% methanol and 1% TEA in EtOAc).
̋̉
ë
= -12.4 (c = 0.17 in CHCl3).
1H NMR (500 MHz, d6-DMSO, 120 oC): δH = 8.69 (1H, d, J = 4.4 Hz, H5), 7.97 (1H, d, J =
9.1 Hz, H3), 7.50 (1H, d, J = 2.6 Hz, H9), 7.43 (1H, dd, J = 9.1, 2.6 Hz, H2), 7.40 – 7.36
(2H, m, ArH), 7.21 - 7.15 (2H, m, ArH), 6.99 – 6.94 (1H, m, ArH), 6.86 – 6.82 (1H, m,
ArH), 6.78 – 6.73 (2H, m, ArH), 6.37 (1H, d, J = 8.1 Hz, H10), 6.02 (1H, ddt, J = 17.2,
10.7, 5.2 Hz, H31), 5.92 (1H, ddt, J = 17.5, 10.5, 7.1 Hz, H18), 5.37 (1H, dq, J = 17.2, 1.6

Hz, H32t), 5.24 (1H, dq, J = 10.7, 1.6 Hz, H32c), 5.04 (1H, dt, J = 17.2, 1.6 Hz, H19t),
5.01 (1H, dt, J = 10.5, 1.6 Hz, H19c), 4.66 - 4.50 (2H, m, H22/H23), 4.52 (2H, dt, J = 5.2,
1.6 Hz, H30), 4.17 (2H, br s, H22/H23), 3.94 (3H, s, H20), 3.73 (2H, br s, H34), 3.35 (1H,
q, J = 8.2 Hz, H11), 3.09 - 3.02 (1H, m, H15a), 2.95 - 2.86 (1H, m, H16a), 2.57 - 2.49
(2H, m, H15b, H16b), 2.27 (1H, br s, H17), 1.88 - 1.86 (1H, m, H12a), 1.83 - 1.79 (1H, m,
H13), 1.72 - 1.66 (1H, m, H14a), 1.54 - 1.43 (2H, m, H12b, H14b).
o
13C NMR (126 MHz, d6-DMSO, 120 C): δC = 147.5 (C5), 142.4 (C18), 135.2 (sp2-C),
134.1 (C31), 134.0 (sp2-C), 131.5 (C3), 129.6, 128.7, 125.5, 122.3 (sp2-C), 121.0 (C2),
120.1, 118.8 (sp2-C), 117.2 (C32), 114.3 (2 x sp2-C), 103.2 (C9), 74.5 (C10), 68.4 (C30),
59.5 (C11), 56.3 (C16), 55.7 (C20), 42.0 (C15), 39.4 (C17), 27.7 (C13), 27.3 (C14), 24.8
(C12).
Some quaternary peaks were not observed. Due to the rotameric effects of the amide,
carbons 22, 23 and 34 were also not observed.
HRMS (ESI+): m/z found [M+H]+ 652.2839, C38H42O5N3S required 652.2840.
Modified from a literature procedure.54
4.2.3.2 Ester (36)
A solution of quinine (1.00 g, 3.08 mmol), undecylenic acid (622 µL, 3.08 mmol) and
DMAP (37.6 mg, 308 µmol) in CH2Cl2 (6 mL) was cooled to 0 oC, after which a solution of
DCC (700 mg, 3.39 mmol) in CH2Cl2 (2 mL) was added. The solution was stirred at rt for
24 h. The reaction mixture was diluted with CH2Cl2 (20 mL) and washed successively
with saturated aqueous NaHCO3 solution (2 x 30 mL), H2O (30 mL), brine (30 mL) and
dried (MgSO4). The solution was filtered and the solvent removed under reduced
pressure. The crude product was purified by flash column chromatography on TEA-
deactivated silica, eluting with CH2Cl2 to yield the title compound as a viscous pale yellow
oil (950 mg, 1.94 mmol, 63%).
Rf = 0.79 (10% methanol in CH2Cl2, TEA-deactivated SiO2).
̋̉
ë
= -22.0 (c = 0.05 in MeOH).
IR: λmax = 2927 (s, C–H), 2857 (m, C–H), 1739 (s, C=O), 1622 (s, C=C), 1593 (w, C=C),
1508 (s, C=C).
1H NMR (500 MHz, CDCl3): δH = 8.76 (1H, d, J = 4.4 Hz, H5), 7.84 (1H, d, J = 9.2 Hz,
H3), 7.47 (1H, d, J = 2.7 Hz H9), 7.39 (1H, dd, J = 9.2, 2.7 Hz, H2), 7.36 (1H, d, J = 4.4
Hz, H6), 6.53 (1H, d, J = 7.2 Hz, H10), 5.91 – 5.77 (2H, m, H18, H30) 5.07 – 4.93 (4H, m,
H19, H31), 3.98 (3H, s, H20), 3.40 (1H, q, J = 8.1 Hz, H11), 3.20 - 3.04 (2H, m, H15a,
H16a), 2.72 – 2.61 (2H, m, H15b, H16b), 2.39 (2H, t, J = 7.5 Hz, H22), 2.31 (1H, br s,

H17), 2.04 (2H, qt, J = 6.8, 1.4 Hz, H29), 1.94 – 1.85 (2H, m, H12a, H13), 1.77 – 1.70
(1H, m, H14a), 1.66 – 1.51 (4H, m, H12b, H14b, H23), 1.41 – 1.34 (2H, m, H28), 1.30 –
1.23 (8H, m, H24, H25, H26, H27).
13C NMR (126 MHz, CDCl3): δC = 72.9 (C21), 157.6 (C1), 147.3 (C5), 144.6 (sp2-C),
143.2 (sp2- C), 141.6, 138.9 (C18, C30), 131.6 (C3), 126.9 (sp2-C), 121.5 (C2), 118.8
(C6), 114.3, 113.9 (C19, C31), 101.3 (C9), 73.5 (C10), 58.9 (C11), 56.4 (C16), 55.4
(C20), 42.2 (C15), 39.6 (C17), 34.3 (C22), 33.6 (C29), 29.1, 29.0, 28.1, 28.9, 28.8 (sp3-
C), 27.7 (C14), 27.5 (C13), 24.8 (C23), 24.4 (C12).
HRMS (ESI+): m/z found [M+H]+ 491.3289, C31H43O3N2 required 491.3268.
Modified from a literature procedure.54
4.2.3.3 Macrocycle (12)
35 (33.0 mg, 50.6 µmol) and Grubbs’ 2nd generation catalyst (4.30 mg, 5.06 µmol) were
dissolved in CH2Cl2 (10 mL) and refluxed in a sealed tube at 80 oC for 16 h. The solvent
was removed under reduced pressure and the crude product was purified by preparative
HPLC (30-65B) to yield the title compound as an amorphous pale yellow solid (3.10 mg,
5.00 µmol, 10%).
Rf = 0.30 (10% methanol and 1% TEA in Et2O).
̋̉
ë
= -1.00 (c = 0.1 in CHCl3).
IR: λmax = 2925 (m, C–H), 2853 (w, C–H), 1735 (m, C=O), 1647 (m, C=C), 1623 (m,
C=C), 1509 (m, C=C).
1H NMR (500 MHz, d6-DMSO, 120 oC): δH = 8.67 (1H, d, J = 4.4 Hz, H5), 7.93 (1H, d, J =
9.1 Hz, H3), 7.45 (1H, d, J = 2.6 Hz, H9), 7.41 – 7.37 (2H, m, ArH), 7.35 – 7.32 (1H, m,
ArH), 7.10 – 7.03 (4H, m, ArH), 6.91 (1H, d, J = 7.6 Hz, ArH), 6.86 (1H, br s, ArH), 6.13
(1H, d, J = 8.6 Hz, H10), 5.88 (1H, dd, J = 15.9, 3.9 Hz, H18), 5.65 (1H, ddt, J = 16.2,
6.0, 2.1 Hz, H19), 4.78 (2H, d, J = 5.6 Hz, H30), 4.67 (1H, d, J = 15.2 Hz, H22a/H23a),
4.52 (1H, d, J = 15.2 Hz, H22b/H23b), 4.14 (2H, br s, H22/H23/H32), 3.93 (3H, s, H20),
3.74 (2H, br s, H22/H23/H32), 2.89 – 2.82 (1H, m, H15a), 2.75 (1H, app q, J = 9.4 Hz,
H11), 2.65 (1H, dd, J = 13.3, 9.4 Hz, H16a), 2.53 – 2.51 (1H, m, H16b), 2.37 (1H, t, J =
11.0 Hz, H15b), 2.21 – 2.18 (1H, m, H17), 1.81 (1H, br s, H13), 1.62 – 1.56 (1H, m,
H14a), 1.43 - 1.36 (2H, m, H12a, H14b), 0.99 – 0.94 (1H, m, H12b).
13C NMR (126 MHz, d6-DMSO): δC = 170.3 (C21), 168.6 (C31), 158.0 (sp2-C), 157.6
(sp2-C), 157.5 (sp2-C), 147.6 (C5), 146.0 (sp2-C), 140.4 (C18), 138.6 (sp2-C), 135.5 (sp2-
C), 131.3 (C3), 129.7 (C9), 129.3 (sp2-C), 126.8 (sp2-C), 126.0 (sp2-C), 124.4 (C19),
122.8 (sp2-C), 121.9 (sp2-C), 4 x 116.9 (sp2-C), 102.0 (sp2-C), 66.7 (C30), 56.0 (C20),
54.2 (C16), 53.1 (C22/C23), 50.4 (C22/C23/C32), 41.7 (C15), 35.5 (C17), 34.2
(C22/C23/C32), 25.2 (C13), 27.1 (C14), 26.1 (C12).
Carbons 10 and 11 were not observed.
HRMS (ESI+): m/z found [M+H]+ 624.2523, C36H38O5N3S required 624.2527.
4.2.3.4 Macrocycle (13)

To a stirred solution of 36 (50.0 mg, 102 µmol) in CH2Cl2 (20 mL) was added Grubbs’ 2nd
generation catalyst (8.69 mg, 10.2 µmol). The solution was subsequently degassed and
refluxed at 40 oC for 18 h under an Ar atmosphere, after which the solvent was removed
under reduced pressure. The crude product was purified by preparative HPLC (40-60B)
to yield the title compound as an off-white amorphous solid (8.50 mg, 18.4 µmol, 18%).
Rf = 0.11 (50% EtOAc in petroleum ether 40-60, TEA-deactivated SiO2).
̋̉
ë
= -52.6 (c = 0.27 in CHCl3).
IR: λmax = 2928 (s, C–H), 2853 (m, C–H), 1731 (s, C=O), 1622 (m, C=C), 1509 (m, C=C).
1H NMR (400 MHz, d4-MeOH): δH = 8.80 (1H, d, J = 4.4 Hz, H5), 8.04 (1H, d, J = 9.1 Hz,
H3), 7.55 (1H, d, J = 2.7 Hz, H9), 7.42 (1H, d, J = 4.4 Hz, H6), 7.38 (1H, dd, J = 9.3, 2.7
Hz, H2), 6.52 (1H, d, J = 10.5 Hz, H10), 5.55 – 5.47 (2H, m, H18, H19), 3.98 (3H, s,
H29), 3.50 (1H, q, J = 9.0 Hz, H11), 3.01 - 2.93 (1H, m, H15a), 2.88 – 2.80 (2H, m, H16),
2.59 (1H, t, J = 11.5 Hz, H15b), 2.39 – 2.24 (4H, m, H12a, H17, H27), 2.22 – 2.13 (2H,
m, H20), 2.01 (1H, s, H13), 1.80 – 1.68 (2H, m, H14), 1.63 – 1.25 (13H, m, H12b, H21,
H22, H23, H24, H25, H26).ꢀ
13C NMR (101 MHz, d4-MeOH): δC = 172.5 (C28), 158.2 (C1), 146.9 (C5), 144.0 (sp2-C),
134.2 (C18), 130.2 (C3), 128.9 (C19), 127.9 (sp2-C), 122.4 (sp2-C), 121.9 (C2), 120.9
(C6), 102.1 (C9), 73.0 (C10), 58.7 (C11), 54.9 (C29), 53.9 (C16), 41.9 (C15), 36.0 (C17),
34.4 (C27), 32.7 (C20), 28.8, 28.4, 27.8, 2 x 27.7, 27.3, 26.7, 26.6, 24.3 (sp3-C).
HRMS (ESI+): m/z found [M+H]+ 463.2950, C29H39O3N2 required 463.2955.
4.2.4 Macrocycles from structural class Mac 2
4.2.4.1 Ester (38)
A solution of 3 (500 mg, 1.24 mmol), 33 (220 mg, 1.24 mmol), EDCI (713 mg, 3.72 mmol)
and DMAP (606 mg, 4.96 mmol) in CH2Cl2 (10 mL) was stirred at rt for 23 h. The solution
was diluted with EtOAc (30 mL), washed successively with H2O (2 x 20 mL), brine (20
mL) and dried (MgSO4). The solution was filtered and the solvent removed under
reduced pressure. The crude product was purified by flash column chromatography on
silica, eluting with a gradient from 0% to 8% MeOH in Et2O with 1% TEA. A small amount
of still impure material was then purified by preparative HPLC (30-65B) to yield the title
compound as an off-white oil (23.6 mg, 42.0 µmol, 3%).

Rf = 0.11 (10% methanol and 1% TEA in Et2O).
̋̉
ë
= -90.6 (c = 0.31 in MeOH).
IR: λmax = 3146 (br, O–H), 2931 (m, C–H), 2096 (s, -N3), 1718 (s, C=O), 1621 (m, C=C),
1591 (m, C=C), 1509 (m, C=C).
1H NMR (500 MHz, d4-MeOH): δH = 8.68 (1H, d, J = 4.6 Hz, H5), 7.96 - 7.94 (2H, m,
ArH), 7.91 (1H, dt, J = 7.9, 1.5 Hz, H29), 7.71 (1H, d, J = 4.6 Hz, H6), 7.58 (1H, d, J = 7.6
Hz, H27), 7.48 (1H, t, J = 7.6 Hz, H28), 7.43 - 7.41 (2H, m, ArH), 5.73 (1H, s, H10), 4.43
(2H, s, H30), 4.40 (2H, t, J = 6.4 Hz, H22), 3.98 (3H, s, H20), 3.89 - 3.83 (1H, m, H15a),
3.35 - 3.26 (2H, m, H11, H16a), 2.91 - 2.85 (1H, m, H15b), 2.82 (2H, t, J = 6.7 Hz, H21),
2.67 - 2.62 (1H, m, H16b), 2.55 (2H, t, J = 7.3 Hz, H19), 2.03 - 1.85 (4H, m, H12a, H13,
H14a, H17), 1.67 - 1.39 (4H, m, H12b, H14b, H18).
13C NMR (126 MHz, d4-MeOH): δC = 167.3 (C23), 159.9 (C1), 148.2 (C5), 149.3, 144.8,
138.0 (sp2-C), 134.1 (C27), 131.8, 131.5, 130.3 (sp2-C), 130.2 (C29), 130.1 (C28), 127.9,
123.4 (sp2-C), 120.3 (C6), 102.5 (C9), 70.8 (C10), 65.4 (C22), 61.6 (C11), 58.4 (C16),
56.7 (C20), 55.0 (C30), 44.6 (C15), 35.1 (C18), 35.0 (C13/17), 31.3 (C21), 30.7 (C19),
27.5 (C14), 26.6 (C13/C17), 20.7 (C12).
HRMS (ESI+): m/z found [M+H]+ 562.2478, C30H36O4N5S required 562.2483.
Modified from a literature procedure.55
4.2.4.2 Ester (39)
A solution of 3 (100 mg, 248 µmol), 4-pentynoic acid (24.3 mg, 248 µmol), EDCI (143
mg, 744 µmol) and DMAP (121 mg mg, 992 µmol) in CH2Cl2 (2 mL) was stirred at rt for
16 h. The solution was diluted with EtOAc (30 mL), washed successively with H2O (2 x
20 mL), brine (20 mL) and dried (MgSO4). The solution was filtered and the solvent
removed under reduced pressure. The crude product was purified by flash column
chromatography on silica, eluting with 5% MeOH in EtOAc with 1% TEA to yield the title
compound as a colourless oil (67.9 mg, 141 µmol, 57%).
Rf = 0.13 (5% methanol and 1% TEA in EtOAc).
̋̉
ë
= -82.3 (c = 0.22 in CHCl3).
IR: λmax = 2925 (s, C–H), 1736 (s, C=O), 1621 (m, C=C), 1591 (w, C=C), 1509 (m, C=C).
1H NMR (400 MHz, CDCl3): δH = 8.73 (1H, d, J = 4.4 Hz, H5), 8.01 (1H, d, J = 9.2 Hz,
H3), 7.54 (1H, d, J = 4.4 Hz, H6), 7.35 (1H, dd, J = 9.2, 2.7 Hz, H2), 7.25 (1H, d, J = 2.4
Hz, H9), 5.63 (1H, br s, H10), 4.23 (2H, t, J = 7.2 Hz, H22), 3.92 (3H, s, H20), 3.57 – 3.46
(1H, m, H15a), 3.19 – 3.11 (2H, m, H11, H16a), 2.76 – 2.68 (1H, m, H15b), 2.71 (2H, t, J

= 7.2 Hz, H21), 2.58 – 2.41 (7H, m, H16b, H19, H24, H25), 1.99 (1H, t, J = 2.4 Hz, H27),
1.85 – 1.68 (4H, m, H12a, H13, H14a, H17), 1.64 – 1.47 (4H, m, H12b, H14b, H18).ꢀ
13C NMR (101 MHz, CDCl3): δC = 171.5 (C23), 157.8 (C1), 147.6 (C5), 147.1, 144.3 (sp2-
C), 131.7 (C3), 126.6 (sp2-C), 121.6 (C2), 118.4 (C6), 101.2 (C9), 82.3 (C26), 71.8 (C10),
69.1 (C27), 63.5 (C22), 59.8 (C11), 58.2 (C16), 55.8 (C20), 43.2 (C15), 34.6 (C17), 34.5
(C18), 33.2 (C19/C24/C25), 30.5 (C21), 30.3 (C19/C24/C25), 27.9 (C12), 25.6 (C13),
21.5 (C14), 14.4 (C19/C24/C25).
HRMS (ESI+): m/z found [M+H]+ 483.2309, C27H35O4N2S required 483.2312.
Modified from a literature procedure.55
4.2.4.3 Ester (41)
A solution of 39 (60.0 mg, 124 µmol), 27 (20.78 mg, 124 µmol) and DMAP (1.51 mg, 12.4
o
µmol) in CH2Cl2 (0.5 mL) was cooled to 0 C, after which a solution of DCC (28.1 mg,
136 µmol) in CH2Cl2 (0.5 mL) was added. The solution was stirred at rt for 25 h. The
reaction mixture was diluted with EtOAc (10 mL) and washed successively with H2O (10
mL), saturated aqueous NaHCO3 solution (10 mL), H2O (10 mL), brine (10 mL) and dried
(Na2SO4). The solution was filtered and the solvent removed under reduced pressure.
The crude product was purified by flash column chromatography on silica, eluting with a
gradient from 0% to 2% MeOH in EtOAc with 1% TEA to yield the title compound as an
amorphous yellow solid (41.3 mg, 65.4 µmol, 53%).
Rf = 0.24 (1% TEA in EtOAc).
̋̉
ë
= +27.0 (c = 0.10 in CHCl3).
IR: λmax = 2921 (w, C–H), 2099 (w, -N3), 1729 (m, C=O), 1674 (w, C=O), 1621 (m, C=C),
1593 (w, C=C), 1509 (m, C=C).
1H NMR (500 MHz, d4-MeOH): δH = 8.69 (1H, d, J = 4.7 Hz, H5), 8.02 (1H, d, J = 9.2 Hz,
H3), 7.61 (1H, d, J = 4.7 Hz, H6), 7.59 (1H, d, J = 2.9 Hz, H9), 7.51 (1H, dd, J = 9.2, 2.6
Hz, H2), 7.47 (1H, d, J = 3.4 Hz, H30), 6.79 (1H, d, J = 4.4 Hz, H10) 6.69 (1H, d, J = 3.7
Hz, H31), 4.50 (2H, s, H33), 4.21 (2H, dd, J = 7.1, 2.1 Hz, H22), 4.05 (3H, s, H20), 3.60 –
3.56 (1H, m, H11), 3.40 – 3.34 (1H, m, H15a), 3.24 – 3.19 (1H, m, H16a), 2.88 – 2.81
(1H, m, H15b), 2.72 (2H, t, J = 7.6 Hz, H21), 2.60 – 2.56 (1H, m, H16b), 2.56 (2H, t, J =
7.6 Hz, H19), 2.52 – 2.49 (2H, m, H24), 2.45 – 2.41 (2H, m, H25), 2.26 (1H, t, J = 2.6 Hz,
H27), 2.09 – 1.84 (5H, m, H12, H13, H14a, H17), 1.73 – 1.61 (3H, m, H14b, H18).
13C NMR (126 MHz, d4-MeOH): δC = 173.3 (C23/C28), 160.1, 158.4, 156.6 (C1, C29,
C32), 148.2 (C5), 145.5 (sp2-C), 145.1 (sp2-C), 131.8 (C3), 128.0 (sp2-C), 123.9 (C2),
121.3 (C30), 120.0 (C6), 112.5 (C31), 102.4 (C9), 83.3 (C26), 75.5 (C10), 70.2 (C27),
64.7 (C22), 60.0 (C11), 58.9 (C16), 56.6 (C20), 47.6 (C33), 44.0 (C15), 35.4 (C13/C17),
35.3 (C18), 34.3 (C24), 31.0 (C21), 30.7 (C19), 28.5 (C14), 26.7 (C13/C17), 23.4 (C12),
15.0 (C25).
One carbonyl carbon missing (C23/C28).
HRMS (ESI+): m/z found [M+H]+ 632.2520, C33H38O6N5S required 632.2537.
Modified from a literature procedure.54

4.2.4.4 Macrocycle (14)
41 (20.0 mg, 31.7 µmol) was dissolved in dry THF (30 mL) and DIPEA (16.7 µL, 95.7
µmol) was added. After bubbling argon through the solution for 20 min, CuI (24.2 mg,
127 µmol) was added and the mixture was refluxed for 10 h until HPLC indicated
complete conversion of the starting material. Subsequently, the solvent was removed
under reduced pressure and the residue was dissolved in CH2Cl2/MeOH/TEA 10:1:0.1
and filtered through a pad of SiO2. The crude product was purified by preparative HPLC
(5-55B) to yield the title compound as an amorphous pale yellow solid (4.2 mg, 6.65
µmol, 21%).
Rf =0.17 (10% methanol and 1% TEA in EtOAc).
̋̉
ë
= +137 (c = 0.14 in CHCl3).
IR: λmax = 2924 (m, C–H), 1722 (s, C=O), 1619 (m, C=C), 1598 (w, C=C), 1538 (w,
C=C), 1508 (s, C=C).
1H NMR (500 MHz, d6-DMSO): δH = 8.68 (1H, d, J = 4.6 Hz, H5), 8.01 (1H, s, H27), 7.94
(1H, d, J = 9.2 Hz, H3), 7.53 (1H, d, J = 2.8 Hz, H9), 7.45 (1H, d, J = 4.6 Hz, H6), 7.42
(1H, dd, J = 9.2, 2.4 Hz, H2), 7.31 (1H, d, J = 3.4 Hz, H31), 6.84 (1H, d, J = 3.7 Hz, H30),
6.41 (1H, d, J = 7.6 Hz, H10), 5.78 (1H, d, J = 15.6 Hz, H28a), 5.74 (1H, d, J = 15.8 Hz,
H28b), 4.21 (2H, t, J = 6.1 Hz, H22), 3.88 (3H, s, H20), 3.47 - 3.40 (1H, m, H11), 3.09 -
3.00 (1H, m, H15a), 2.97 - 2.93 (2H, m, H24/H25), 2.82 - 2.69 (5H, m, H16a, H21,
H24/H25), 2.63 - 2.50 (2H, m, H19), 2.47 - 2.41 (1H, m, H15b), 2.12 (1H, d, J = 13.1 Hz,
H16b), 1.87 - 1.81 (1H, m, H12a), 1.79 - 1.70 (2H, m, H13/H17, H18a), 1.65 - 1.58 (1H,
m, H14a), 1.56 - 1.41 (3H, m, H12b, H13/H17, H18b), 1.33 - 1.26 (1H, m, H14b).
13C NMR (126 MHz, d6-DMSO): δC = 173.3 (C23/C33), 157.7, 157.3, 153.2 (C1, C29,
C32), 148.0 (C5), 146.3 (sp2-C), 144.4 (sp2-C), 144.3 (sp2-C), 131.8 (C3), 127.3 (sp2-C),
123.1 (C27), 122.0 (C2), 121.0 (C31), 119.3 (C6), 112.6 (C30), 102.6 (C9), 74.3 (C10),
65.5 (C22), 60.0 (C11), 57.6 (C16), 56.0 (C20), 46.1 (C28), 42.1 (C15), 35.2 (C18), 34.9
(C13/C17), 33.6 (C24/C25), 30.7 (C19), 30.2 (C21), 28.1 (C14), 24.5, 24.5 (C12,
C13/C17), 21.2 (C24/C25). Missing C23/C33.
HRMS (ESI+): m/z found [M+H]+ 632.2525, C33H38O6N5S required 632.2537.
4.2.4.5 Macrocycle (15)

40 (21.3 mg, 24.9 µmol) was dissolved in dry THF (30 mL) and DIPEA (13.0 µL, 74.7
µmol) was added. After bubbling argon through the solution for 20 min, CuI (19.0 mg,
99.8 µmol) was added and the mixture was refluxed for 46 h until HPLC indicated
complete conversion of the starting material. Subsequently, the solvent was removed
under reduced pressure and the residue was dissolved in CH2Cl2/MeOH/TEA 10:1:0.1
and filtered through a pad of SiO2. The crude product was purified by preparative HPLC
(20-70B) to yield the title compound as an pale brown amorphous solid (2.2 mg, 2.58
µmol, 10%).
HPLC tr = 8.68 min (20-70B).
̋̉
ë
= -8.79 (c = 0.33 in CHCl3).
IR: λmax = 2926 (m, C–H), 2857 (m, C–H), 1720 (s, C=O), 1647 (m, C=C), 1621 (m,
C=C), 1510 (s, C=C).ꢀ
1H NMR (500 MHz, d6-DMSO): δH = 8.85 (1H, d, J = 4.3 Hz, H5), 8.68 (1H, br s, ArH),
8.22 (1H, br s, ArH), 8.03 (1H, d, J = 9.5 Hz, H3), 8.01 (1H, d, J = 7.9 Hz, ArH), 7.85*
(1H, d, J = 7.6 Hz, ArH), 7.53 (2H, d, J = 8.5 Hz, ArH), 7.51 (1H, dd, J = 9.2, 2.8 Hz, H2),
7.27* (2H, d, J = 2.8 Hz, H9), 7.22 - 7.18 (2H, m, ArH), 7.05 (1H, br s, ArH), 6.55 (1H, br
s, H10), 5.78 (2H, br s, H30), 5.02 (1H, d, J = 15.6 Hz, H33a/H35a/H40a), 4.66 (1H, d, J
= 16.2 Hz, H33b/H35b/H40b), 4.54 - 4.49 (1H, m, H22a), 4.45 - 4.39 (1H, m, H22b), 4.34
(1H, d, J = 16.2 Hz, H33a/H35a/H40a), 4.26 (1H, d, J = 15.6 Hz, H33a/H35a/H40a), 4.22
(1H, d, J = 16.5 Hz, H33b/H35b/H40b), 3.92 (1H, d, J = 16.2 Hz, H33b/H35b/H40b), 3.91
(3H, s, H20) 3.58 - 3.53** (1H, m, H11), 3.31 - 3.00** (1H, m, H15a/H16a), 2.97 - 2.74
(5H, m, H15a/H16a, H15b, H16b, H21), 2.43 - 2.32 (2H, m, H19), 1.67 (1H, br s, H17),
1.29 - 1.01 (5H, m, H12, 13, 14), 0.75 (1H, br s, sp3-H), 0.50 (1H, br s, sp3-H).
* = HSQC indicates possible presence of rotamers.
** = obscured by H2O peak, assigned from HSQC.
13C NMR (126 MHz, d6-DMSO): δC = 171.8, 168.3, 165.6 (C23, C34, C41), 158.5, 158.4,
158.3 (sp2-C), 147.7 (C5), 144.0, 143.3, 140.6, 136.7, 134.9, 134.8, 132.3 (sp2-C), 131.8
(C3), 131.5, 130.4, 129.6, 125.6, 124.5 (sp2-C), 122.3 (C2), 120.2, 118.0 (sp2-C), 102.3
(C9), 70.1* (C10), 66.0 (C22), 56.8 (C11), 56.4 (C20), 54.4 (C15/C16), 53.1 (C30), 52.1
(C33/C35/C40), 44.4 (C33/C35/C40), 42.2 (C15/C16/C21), 38.9 (C33/C35/C40), 33.7
(sp3-C), 32.2 (C17), 31.0 (C15/C16/C21), 30.2 (C19), 29.1* (sp3-C), 24.4 (C13), 23.6
(sp3-C). * = assigned from HSQC.
HRMS (ESI+): m/z found [M+H]+ 853.2353, C43H46O6N6S79Br required 853.2383.
4.2.5 Macrocycles from structural class Mac3
4.2.5.1 Amide (42)
A solution of 2 (700 mg, 2.16 mmol) and 8-nonenoic acid (337 mg g, 2.16 mmol) in DMF
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(10 mL) was cooled to 0 C, after which HATU (819 mg, 2.16 mmol), DIPEA (826 µL,
4.75 mmol) and DMAP (26.3 mg, 216 µmol) were added. The solution was allowed to
warm to rt and stirred for 15 h. The reaction mixture was quenched with a saturated
aqueous LiCl solution (40 mL) and extracted with EtOAc (3 x 40 mL). The organic layers
were combined, washed successively with saturated aqueous NaHCO3 (2 x 30 mL),
saturated aqueous LiCl (3 x 30 mL) and brine (40 mL) and dried (MgSO4). The solution
was filtered and solvent removed under reduced pressure. The crude product was
purified by flash column chromatography on TEA-deactivated silica, eluting with a

gradient from 0% to 2% MeOH in CH2Cl2 to yield the title compound as a yellow oil (628
mg, 1.36 µmol, 63%).
Rf = 0.79 (10% methanol in CH2Cl2, TEA-deactivated SiO2).
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= +22.5 (c = 0.16 in MeOH).
IR: λmax = 2928 (m, C–H), 2855 (m, C–H), 1688 (m, C=O), 1635 (s, C=C), 1618 (s, C=C),
1504 (m, C=C).
1H NMR (500 MHz, d6-DMSO, 120 oC): δH = 8.88 (1H, d, J = 4.4 Hz, H5), 8.03 (1H, d, J =
8.4 Hz, H3), 7.78 (1H, d, J = 4.4 Hz, H6), 7.70 (1H, d, J = 2.9 Hz, H9), 7.49 (1H, dd, J =
9.1, 2.9 Hz, H2), 5.88 – 5.76 (2H, m, H18, H27), 5.17 (1H, d, J = 17.5 Hz, H19t), 5.11
(1H, d, J = 10.5 Hz, H19c), 5.01 (1H, dt, J = 17.2, 5.03 Hz, H28t), 4.94 (1H, d, J = 10.2
Hz, H28c), 4.12 – 3.88 (2H, m, H15a, H16a), 3.92 (3H, s, H29), 3.16 – 3.04 (1H, m,
H16b), 3.12 (2H, t, J = 7.6 Hz, H11), 2.99 – 2.88 (1H, m, H15b), 2.46 – 2.42 (1H, m,
H17), 2.32 - 2.23 (2H, m, H21), 2.04 (2H, t, J = 7.1 Hz, H26), 1.84 – 1.79 (1H, m, H13),
1.73 – 1.62 (2H, m, H12), 1.58 – 1.51 (3H, m, H14a, H25), 1.42 – 1.30 (7H, m, H14b,
H22, H23, H24).ꢀ
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13C NMR (126 MHz, d6-DMSO, 120 C): δC = 203.3 (C10), 170.2 (C20), 158.1 (C1),
146.8 (C5), 144.4 (sp2-C), 140.6 (sp2-C), 138.1 (C18/C27), 135.7 (C18/C27), 130.5 (C3),
123.9 (sp2-C), 121.0 (C2), 119.4 (C6), 116.9 (C19), 113.6 (C19/C28), 103.6 (C9), 55.0
(C29), 42.6 (C17), 38.7 (C11), 38.6, 38.3 (C15, C16), 37.4 (C13), 32.2 (C26), 31.7 (C21),
27.9, 27.9, 27.5 (C22, C23, C24), 26.8 (C14), 25.9 (C12), 24.2 (C25).
HRMS (ESI+): m/z found [M+H]+ 463.2961, C29H39O3N2 required 463.2955.
4.2.5.2 Amide (43)
A solution of 2 (700 mg, 2.16 mmol) and undecylenic acid (398 mg, 2.16 mmol) in DMF
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(10 mL) was cooled to 0 C, after which HATU (819 mg, 2.16 mmol), DIPEA (826 µL,
4.75 mmol) and DMAP (26.3 mg, 216 µmol) were added. The solution was allowed to
warm to rt and stirred for 40 h. The reaction mixture was quenched with a saturated
aqueous LiCl solution (30 mL) and extracted with EtOAc (3 x 30 mL). The organic layers
were combined, washed successively with saturated aqueous NaHCO3 solution (2 x 30
mL), saturated aqueous LiCl solution (3 x 30 mL), brine (30 mL) and dried (MgSO4). The
solution was filtered and solvent removed under reduced pressure. The crude product
was purified by flash column chromatography on TEA-deactivated silica, eluting with a
gradient from 0% to 2% MeOH in CH2Cl2 to yield the title compound as a yellow oil (570
mg, 1.16 µmol, 54%).
Rf = 0.89 (10% methanol in CH2Cl2, TEA-deactivated SiO2).
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ë
= +20.5 (c = 0.19 in MeOH).
IR: λmax = 2926 (m, C–H), 2854 (m, C–H), 1689 (m, C=O), 1637 (s, C=C), 1617 (s, C=C),
1504 (m, C=C).
1H NMR (500 MHz, d6-DMSO, 120 oC): δH = 8.87 (1H, d, J = 4.2 Hz, H5), 8.03 (1H, d, J =
9.1 Hz, H3), 7.78 (1H, d, J = 4.4 Hz, H6), 7.70 (1H, d, J = 2.6 Hz, H9), 7.49 (1H, dd, J =
9.2, 2.9 Hz, H2), 5.87 – 5.76 (2H, m, H18, H30), 5.18 (1H, d, J = 18.0 Hz, H19t), 5.11
(1H, d, 10.5 Hz, H19c), 5.00 (1H, d, J = 17.2 Hz, H31t), 4.94 (1H, d, J = 10.2 Hz, H31c),
4.19 – 3.88 (2H, m, H15a, H16a), 3.93 (3H, s, H20), 3.18 – 3.04 (1H, m, H16b), 3.12 (2H,
t, J = 7.6 Hz, H11), 2.99 – 2.86 (1H, m, H15b), 2.45 – 2.43 (1H, m, H17), 2.33 – 2.23 (2H,

m, H22), 2.04 (2H, t, J = 7.1 Hz, H29), 1.84 – 1.77 (1H, m, H13), 1.73 – 1.62 (2H, m,
H12), 1.58 – 1.28 (14H, m, H14, H23, H24, H25, H26, H27, H28).
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13C NMR (500 MHz, d6-DMSO, 120 C): δC = 204.3 (C10), 171.3 (C21), 159.2 (C1),
147.8 (C5), 145.4 (sp2-C), 141.7 (sp2-C), 139.1 (C18/C30), 136.7 (C18/C30), 131.5 (C3),
124.9 (sp2-C), 122.0 (C2), 120.4 (C6), 116.7 (C19), 114.5 (C31), 104.6 (C9), 56.0 (C20),
42.6 (C17), 39.8 (C11), 39.6 (C15/C16), 39.3 (C15/C16), 38.4 (C13), 35.3 (C29), 32.7
(C22), 29.1, 2 x 29.0, 28.7, 28.6, 27.9*, 26.9, 25.2 (sp3-C). * = assigned from HSQC.
HRMS (ESI+): m/z found [M+H]+ 491.3277, C31H43O3N2 required 491.3268.
4.2.5.3 Macrocycle (16)
To a stirred solution of 42 (100 mg, 216 µmol) in toluene (30 mL) was added Grubbs’ 2nd
generation catalyst (18.4 mg, 20.4 µmol). The solution was subsequently degassed and
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refluxed at 120 C for 19 h under an Ar atmosphere, after which an additional 0.1 eq. of
Grubbs’ 2nd generation catalyst was added. The reaction was refluxed for a further 28 h,
after which the solvent was removed under reduced pressure. The crude product was
purified by preparative HPLC (40-70B) to yield the title compound as an amorphous light
brown solid (5.20 mg, 12.0 µmol, 6%).
HPLC tr = 11.16 min (20-70B).
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ë
= +58.0 (c = 0.05 in CHCl3).
IR: λmax = 2927 (s, C–H), 2857 (m, C–H), 1685 (m, C=O), 1618 (s, C=C), 1506 (m, C=C).
1H NMR (500 MHz, CDCl3): δH = 8.90 (1H, br s, H5), 8.09 (1H, d, J = 8.9 Hz, H3), 7.88
(1H, br s, H6), 7.63 (1H, br s, H9), 7.45 (1H, d, J = 8.9 Hz, H2), 5.54 - 5.51 (2H, m, H18,
H19), 4.89 (1H, d, J = 12.3 Hz, H15a), 3.99 - 3.95 (1H, m, H16a), 3.97 (3H, s, H27), 3.31
(1H, d, J = 10.7 Hz, H16b), 3.13 - 2.97 (2H, m, H25), 2.76 (1H, t, J = 12.0 Hz, H11a),
2.57 - 2.52 (1H, m, H15b), 2.48 - 2.46 (1H, m, H17), 2.27 - 2.17 (2H, m, H11b, H20a),
2.10 - 2.02 (1H, m, H20b), 1.93 - 1.88 (1H, m, H12a), 1.82 - 1.77 (2H, m, H13, H14a),
1.75 - 1.13 (10H, m, H12b, H14b, H21, H22, H23, H24).
13C NMR (126 MHz, d6-DMSO): δC = 204.7 (C10), 171.3 (C26), 159.0 (C1), 148.0 (C5),
145.1 (sp2-C), 141.0 (sp2-C), 131.5 (C18/C19), 131.1 (C3), 130.1 (C18/C19), 124.9 (sp2-
C), 122.6 (C2), 121.2 (C6), 103.8 (C9), 55.9 (C27), 55.0 (C16), 42.4 (C15), 41.2 (C17),
39.1 (C25), 37.9 (C13), 30.0, 28.5, 27.2, 26.9, 25.0, 24.9, 24.3, 22.8 (sp3-C).
ꢀHRMS (ESI+): m/z found [M+H]+ 435.2639, C27H35O3N2 required 435.2642.
4.2.5.4 Macrocycle (17)
To a stirred solution of 43 (100 mg, 204 µmol) in toluene (40 mL) was added Grubbs’ 2nd
generation catalyst (17.4 mg, 20.4 µmol). The solution was subsequently degassed and
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re- fluxed at 80 C for 20 h under an Ar atmosphere, after which an additional 0.1 eq. of