Pd-Catalyzed Decarboxylative Cycloaddition for the Synthesis of Highly Substituted δ-Lactones and Lactams

Article abstract of DOI:10.1021/acs.organomet.0c00646

An efficient palladium-catalyzed decarboxylative cycloaddition process of vinyl cyclic carbonates and vinyloxazolidinones for the synthesis of highly substituted δ-lactone and δ-lactam derivatives was developed. This protocol exhibits several unique characteristics, including broad substrate scope, good functional group tolerance, and operational convenience, which enables a regioselective access to a variety of lactone and lactam scaffolds in moderate to good yield. The redox-neutral catalytic system promotes formation of substituted scaffolds with in situ generation of a cyclic tetra-substituted double bond functionality.

Full text of DOI:10.1021/acs.organomet.0c00646

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Article
Pd-Catalyzed Decarboxylative Cycloaddition for the Synthesis of
Highly Substituted δ‑Lactones and Lactams
Linlin Shi,∥ Yingdong He,∥ Jianxian Gong,* and Zhen Yang*
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ABSTRACT: An efficient palladium-catalyzed decarboxylative cycloaddition process of vinyl cyclic carbonates and vinyl-
oxazolidinones for the synthesis of highly substituted δ-lactone and δ-lactam derivatives was developed. This protocol exhibits
several unique characteristics, including broad substrate scope, good functional group tolerance, and operational convenience, which
enables a regioselective access to a variety of lactone and lactam scaffolds in moderate to good yield. The redox-neutral catalytic
system promotes formation of substituted scaffolds with in situ generation of a cyclic tetra-substituted double bond functionality.
Vinyl cyclic carbonates (VCCs) are important building
blocks in organic chemistry owing to their multifaceted
reactivity and ease of preparation.20 Previous work demon-
strated that the Pd-catalyzed decarboxylative construction of
allylic and cyclic derivatives is feasible via the reaction of an
external electrophile or nucleophile with a VCCs under mild
conditions. In this context, many efficient Pd-catalyzed
decarboxylation conversions have been reported by Zhang,21
Kleij,22 Zhao,23 and Glorius24 (Scheme 1b). We recently
reported a Pd-catalyzed allylation to construct allylic amines
and alcohols bearing an all-carbon quaternary center.25,26
Herein, we report a practical and reliable strategy for the
generation of substituted δ-lactones and lactams through a Pd-
catalyzed decarboxylative cycloaddition process (Scheme 1c).
This method successfully forms a C−O and a C−N bond in
addition to installing a tetra-substituted double bond that may
be further functionalized.
INTRODUCTION
■
Lactones and lactams are versatile in organic synthesis and
have found diverse applications in pharmaceuticals, agrichem-
icals, and materials science. In particular, highly substituted
lactones and lactams possess important multifunctional
building blocks in the fields of organic chemistry, agricultural
chemistry, and polymer.1,2 Furthermore, certain highly
substituted δ-lactones and δ-lactams show a variety of
significant biological activities (Scheme 1a).3−7 The prepara-
tion of diversely functionalized lactone and lactam derivatives
has therefore attracted much attention from synthetic
chemists. However, the practical and reliable stereoselective
methodology to direct construction of δ-lactones and lactams
bearing different carbon-linked groups presents a particular
challenge in organic synthesis.8
To date, various methods for the introduction of lactone and
lactam groups have been developed. In this context, the
traditional synthetic methods to these such highly substituted
lactones and lactams involve the direct oxidative C-O or C-N
coupling reaction starting from the corresponding carboxylic
acids.9−12 Despite that great progress has been made in the
field, many of the reported methods have some shortcomings
of harsh conditions. Recently, the transition-metal-catalyzed
carbonylation of organic substrates to highly substituted δ-
lactones and lactams has been extensively studied. This
practical and reliable method has great significance to the
synthesis of carbonyl compounds and their derivates.13−15 The
advantages of transition-metal-catalyzed carbonylation are (i)
it is a reliable way to synthesize carbon heteroatom bonds, and
(ii) it provides an efficient platform and valuable option for the
synthesis of important heterocycle frameworks.16−19
RESULTS AND DISCUSSION
■
First, we investigated a model vinyl cyclic carbonate to
determine the feasibility of forming the corresponding lactone
products via the Pd-catalyzed decarboxylative cycloaddition
process (Table 1). In preliminary experiments, vinyl cyclic
carbonate 1a and the general ligand 1,3-bis-
Received: September 27, 2020
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(THF) (Table 1, entries 5−7). Furthermore, the yield of this
Pd-catalyzed domino process was largely improved increasing
the reaction temperature to 45 °C (Table 1, entry 8).
Scheme 1. (a) Selected Natural Products with an
Unsaturated δ-Lactone and Lactam Core, (b) Reaction of
VCCs, (c) This Work
After systematically investigating the catalyst, solvent, and
reaction temperature, we used the optimized reaction
conditions to study the substrate scope of the Pd-catalyzed
decarboxylative cycloaddition process. To demonstrate the
synthetic utility of the developed method to construct
functionally diverse δ-lactones, the initial vinyl cyclic
carbonates were prepared from easily available 2-hydroxy
acids.22 To our delight, under the optimized reaction
conditions, all the selected substrates afforded the correspond-
ing δ-lactone products (2a−2j, Table 2) with good to excellent
Table 2. Substrate Scope of the Pd-Catalyzed
a
Decarboxylative Cycloaddition Process
(diphenylphosphino)propane were exposed to a CO atmos-
phere under balloon pressure.25,26
a
Table 1. Optimized Reaction Conditions
a
Reaction conditions: 1 (0.2 mmol), Pd (6 mol %), DPPP (10 mol
%), CH3CN (2 mL), 45 °C, 6 h, under CO (1 atm). All yields are
those of the isolated products.
b
entry
Pd catalyst
solvent
temperature (°C)
yield
1
2
[Pd2(dba)3]-CHCl3
Pd(dba)2
PdCl2
DCM
DCM
DCM
DCM
DCM
CH3CN
THF
CH3CN
CH3CN
rt
rt
rt
rt
rt
rt
rt
45
50
yields. Various para-, meta-, and ortho-substituents with both
electron-rich and electron-poor functional groups were well
tolerated on the aromatic group of the substituted vinyl cyclic
carbonates. Product 2d was amenable to crystallization, and
subsequent X-ray structural analysis confirmed its identity.27
As shown in Table 2, aryl-substituted lactones with electron-
donating groups at the para position of the aromatic ring (2b−
2d) offered better yields than aryl-substituted lactones with
electron-withdrawing groups (2e−2g). More sterically hin-
dered substrates afforded the desired products in moderate to
good yields (2h−2j).
As shown in Table 3, this process tolerated carbonate
substrates with a range of functional groups, including aliphatic
systems and aryl substituents (4a−4f) to produce correspond-
ing δ-lactones attached to bulky tetra-substituted olefin
derivatives. More sterically hindered substrates afforded the
desired products in moderate to good yields (4b, ent-4b). In
order to determine the structure of the starting material and
desired lactone, we carried out single crystal diffraction
experiments to confirm the structure of the target compounds.
c
3
4
trace
trace
14%
50%
42%
85%
79%
c
Pd(Ph3)4
5
6
7
8
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
d
9
a
Reaction conditions: 1a (0.1 mmol), Pd (6 mol %), ligand (10 mol
%), solvent (2 mL), rt, 5 h, under CO (1 atm). Isolated yield. The
trace yield was determined by MS analysis. The reaction was stirred
for 6 h at 50 °C.
b
c
d
Efforts to transform vinyl cyclic carbonate 1a to desired δ-
lactone 2a using a different known Pd source resulted in low
yields or starting material recovery (Table 1, entries 1−4).
Gratifyingly, the corresponding δ-lactone was obtained in
moderate yield when Pd(OAc)2 was used as the Pd source
(entry 5). As a solvent, acetonitrile (CH3CN) gave better
results than dichloromethane (DCM) and tetrahydrofuran
B
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a
are provided in the Supporting Information. As illustrated in
this table, the transformation had good functional group
tolerance with both electron-withdrawing (6c, 6d) and
electron-donating (6a, 6b) substituents of the aryl rings,
giving the desired lactams in good yields. Additionally, a meta-
and ortho-substituted substrate (6e−6g) on the aromatic rings
shows good compatibility.
Table 3. Scope of Vinyl Cyclic Carbonate Substrates 3
To demonstrate the synthetic utility of the Pd-catalyzed
decarboxylative cycloaddition reaction, the gram-scale syn-
thesis of 2a was performed, and the corresponding lactone
product was obtained in 82% yield (Scheme 2). Furthermore,
Scheme 2. Gram-Scale Synthesis and Derivatization
a
Reactions
a
Reaction conditions: 3 (0.2 mmol), Pd (6 mol %), DPPP (10 mol
%), CH3CN (2 mL), 80 °C, 8 h, under CO (1 atm). All yields are
those of the isolated products.
The same reaction conditions were also used for the successful
transformation of a wide range of vinyl cyclic carbonates with
electron-donating (4e, 4f) and electron-withdrawing (4c and
4d) functionalities on the aromatic substituent. It was
necessary to increase the temperature and prolong the reaction
time for the formation of the corresponding lactone products
by using these chiral vinyl cyclic carbonates.
We finally sought to extend the methodology to vinyl-
oxazolidinone substrates, which possess the ability to generate
desired δ-lactams under room temperature (Table 4). The
details related to the optimization of the reaction conditions
a
Table 4. Scope of δ-Lactams Formation
a
Standard conditions: 7 (0.2 mmol), Pd (6 mol %), ligand (10 mol
%), CH3CN (2 mL), rt, 6 h, under CO (1 atm). All yields are those of
the isolated products.
several derivatization reactions were also carried out, and
comparable yields of lactam bearing a tetra-substituted double
bond (8, 9) were also observed. We investigated different
protecting groups for vinyloxazolidinones in their palladium-
catalyzed transformation to δ-lactams. These sulfonyl group-
protected derivatives (11, 12) gave good stereoselectivities and
yields of desired products. The structure of lactam 11 was also
confirmed by X-ray crystallographic analysis.27
CONCLUSION
■
In conclusion, we developed a novel Pd-catalyzed decarbox-
ylative cycloaddition process to synthesize functionalized δ-
lactones and δ-lactams. This useful conversion is characterized
by mild reaction conditions, broad substrate scope, and easy
availability of reactants, thus providing an efficient and concise
route to synthesize some important substituted δ-lactones and
lactams. The practical approach allows the synthesis of lactone
and lactam structures in good to excellent yields and can even
furnish substituted δ-lactones under a very mild reaction
condition. The formation of important highly substituted δ-
a
Reaction conditions: 5 (0.2 mmol), Pd (6 mol %), ligand (10 mol
%), CH3CN (2 mL), rt, 6 h, under CO (1 atm). All yields are those of
the isolated products.
C
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88.06, 73.15, 55.48, 18.58. HRMS (ESI+, MeOH): [M + Na]+ calcd
for C13H14O4Na+: 257.0784; found: 257.0783.
lactone and lactam architectures through this Pd-catalyzed
domino reaction is a supplementary strategy for the synthesis
of complex chemical structures.
1c (806 mg) was obtained in 62% yield as a light yellow liquid. 1H
NMR (400 MHz, CDCl3) δ 7.46−7.37 (m, 2H), 7.32−7.26 (m, 2H),
5.21−5.12 (m, 2H), 4.76 (d, J = 8.5 Hz, 1H), 4.64 (d, J = 8.6 Hz,
1H), 1.73 (s, J = 1.5, 0.8 Hz, 3H), 1.32 (s, 9H). 13C NMR (100 MHz,
CDCl3) δ 13C NMR (101 MHz, CDCl3) δ 154.27, 152.17, 143.12,
135.41, 125.91, 124.97, 113.83, 88.14, 73.24, 34.76, 31.36, 18.64.
HRMS (ESI+, MeOH): [M + Na]+ calcd for C16H20O3Na+:
283.1305, found: 283.1302.
EXPERIMENTAL SECTION
■
General Procedures. Unless otherwise mentioned, reagents were
purchased at the highest commercial quality (>95%) and used
without further purification, unless otherwise stated. Anhydrous
tetrahydrofuran (THF) and toluene (PhMe) were distilled from
sodium-benzophenone; dichloromethane (DCM), acetonitrile
(MeCN), and dimethylformamide (DMF) were distilled from
calcium hydride. All reactions were carried out with magnetic stirring,
and if moisture- or air-sensitive, under an argon gas atmosphere with
dry solvents. External bath temperatures were used to record all
reaction temperatures. Certain cyclic vinyl carbonate substrates 1 are
known compounds and were synthesized according to previously
described methods,22c,d and the related spectrum are showed in the
Supporting Information. The data of new cyclic vinyl carbonate
substrates 1a−1e are listed below. Reactions were monitored by thin-
layer chromatography (TLC) carried out on 0.25 mm Tsingdao silica
gel glass-backed plates (60F-254) and visualized under UV light at
254 nm. Staining was performed with an ethanolic solution of
phosphomolybdic acid and heat as developing agents. Tsingdao silica
gel (60, particle size 0.040−0.063 mm) was used for flash column
chromatography. Yields refer to chromatographically, unless otherwise
1d (726 mg) was obtained in 61% yield as a light yellow liquid. 1H
NMR (400 MHz, CDCl3) δ 7.41−7.36 (m, 2H), 7.34−7.27 (m, 2H),
5.21−5.12 (m, 2H), 4.78 (d, J = 8.7 Hz, 1H), 4.58 (d, J = 8.7 Hz,
1H), 1.71 (s, J = 1.5, 0.8 Hz, 3H). 13C NMR (100 MHz, CDCl3) δ
153.83, 142.58, 137.07, 135.13, 129.25, 126.66, 114.47, 87.61, 73.02,
18.46. HRMS (ESI+, MeOH): [M + Na]+ calcd for C12H11ClO3Na+:
261.0289, found: 261.0292.
1e (732 mg) was obtained in 66% yield as a light yellow liquid. 1H
NMR (400 MHz, CDCl3) δ 7.40−7.29 (m, 2H), 7.14−7.04 (m, 2H),
5.17 (dd, J = 5.7, 1.2 Hz, 2H), 4.77 (d, J = 8.7 Hz, 1H), 4.60 (d, J =
8.7 Hz, 1H), 1.71 (s, J = 1.5, 0.8 Hz, 3H). 13C NMR (100 MHz,
CDCl3) δ 164.16, 161.69, 153.92, 142.73, 134.31, 134.28, 127.25,
127.17, 116.12, 115.90, 114.29, 87.69, 73.09, 18.45. HRMS (ESI+,
MeOH): [M + Na]+ calcd for C12H11FO3Na+: 245.0584, found:
245.0586.
1
1f (830 g) was obtained in 71% yield as a light yellow liquid. H
specified. NMR spectra were recorded on Bru
500 MHz, 13C 125 MHz), Bruker Advance 400 (1H: 400 MHz, 13C
100 MHz), and Bru
ker Advance 300 (1H: 300 MHz, 13C 75 MHz).
̈
ker Advance 500 (1H:
NMR (400 MHz, CDCl3) δ 7.55−7.45 (m, 1H), 7.34 (m, J = 8.3, 7.4,
1.7 Hz, 1H), 7.01 (m, J = 7.6, 1.1 Hz, 1H), 6.92 (dd, J = 8.3, 1.0 Hz,
1H), 5.07−4.97 (m, 2H), 4.95 (d, J = 9.4 Hz, 1H), 4.57 (d, J = 9.4
Hz, 1H), 3.80 (s, 3H), 1.79 (s, J = 1.5, 0.8 Hz, 3H). 13C NMR (100
MHz, CDCl3) δ 155.31, 154.36, 142.21, 130.10, 127.35, 126.85,
121.08, 114.69, 111.30, 87.21, 73.14, 55.45, 18.07. HRMS (ESI+,
MeOH): [M + Na]+ calcd for C13H14O4Na+: 257.0784, found:
257.0787.
̈
̈
The spectra were reported as follows: chemical shift δ in ppm
1
(multiplicity, coupling constant J in Hz, number of protons) for H
NMR spectra and chemical shift δ in ppm for 13C NMR spectra. The
following abbreviations were used to explain the multiplicities: s =
singlet, d = doublet, t = triplet, q = quartet, m = multiplet, or
combinations thereof. Residual solvent peaks of CDCl3 (δ H = 7.26
ppm, δ C = 77.16 ppm) or CD3OD (δ H = 3.31 ppm, δ C = 48.00
ppm) were used as an internal reference, unless otherwise stated. High
resolution mass spectrometric (HRMS) data were recorded on Q-
General Procedure for the Synthesis of Chiral Cyclic Vinyl
Carbonate Substrates 3a−3g, 5a−5g.
TOF-MS instruments (Bru
3000), respectively.
̈
ker Apex IV RTMS and VG Auto Spec-
All air- and moisture-sensitive reactions were carried out in oven-
dried Schlenk tubes under an Ar atmosphere. Solvents were dried
with standard methods and freshly distilled prior to use if needed.
Column chromatography was performed using 200−300 mesh silica
gel. Analytical and preparative thin-layer chromatography (TLC)
plates coated with commercial silica gel GF254 were used to monitor
the reactions and purify products. Compounds 1a−e were synthesized
according to previous literatures.21,24 1H NMR and 13C NMR spectra
were recorded at 400 MHz using TMS as an internal standard. Data
are reported as follows: chemical shift (δ ppm), multiplicity (s =
singlet, d = doublet, t = triplet, q = quartet, m = multiplet),
integration, and coupling constants (J) in hertz (Hz). HRMS were
determined on a Q-Tof Micro or AB SCIEX TripleTOF 6600 MS/
MS System ESI spectrometer. The structure of pincer complexes 2d
(CCDC file number 1911275), 3a (CCDC file number 1917984),
and 11 (CCDC file number 1911274) was further confirmed by X-ray
diffraction collected on a diffractometer with graphite-monochro-
mated Cu Kα radiation.
SI-4: Weinreb amides were prepared according to a reported
procedure.3 Accordingly, to a mixture of the corresponding carboxylic
acid SI-3 (5.0 mmol), N,O-dimethylhydroxylamine hydrochloride
(1.3 equiv), and DMAP (0.1 equiv) in CH2Cl2 (25 mL) at 0 °C were
added NEt3 (1.3 equiv) and EDC (1.3 equiv) successively. The
reaction mixture was stirred at 0 °C for 1 h, then allowed to warm to
room temperature and stirred overnight. The reaction mixture was
diluted with EtOAc (50 mL). The organic layer was washed with 1 N
HCl (3 × 5 mL), aqueous saturated NaHCO3 (3 × 5 mL), and brine
(3 × 5 mL). The combined organic layers were dried over anhydrous
Na2SO4, filtered, and concentrated under reduced pressure. The
resulting residue was purified by flash column chromatography on
silica gel (PE:EA = 10:1) to afford SI-4.
SI-5: To a solution of the respective Weinreb amide SI-4 (1.0
equiv) in THF (20 mL) was added arylmagnesium bromide (1.0 M in
THF, 2.5 equiv) at 0 °C. The reaction was stirred under a N2
atmosphere at room temperature for 2 h. The reaction mixture was
then quenched with saturated aqueous NH4Cl (5 mL), and extracted
with EtOAc (3 × 5 mL). The combined organic layers were dried
over anhydrous Na2SO4. The residue was purified by flash
chromatography on silica (PE:EA = 10:1) to afford the SI-5.
1a (877 mg) was obtained in 62% yield as a light yellow liquid. 1H
NMR (400 MHz, CDCl3) δ 7.65−7.44 (m, 2H), 7.39−7.13 (m, 2H),
5.17 (dd, J = 2.9, 1.2 Hz, 2H), 4.78 (d, J = 8.7 Hz, 1H), 4.58 (d, J =
8.7 Hz, 1H), 1.71 (s, J = 1.5, 0.8 Hz, 3H). 13C NMR (100 MHz,
CDCl3) δ 153.78, 142.44, 137.57, 132.15, 126.91, 123.20, 114.46,
87.61, 72.92, 18.40. HRMS (ESI+, MeOH): [M + Na]+ calcd for
C12H11BrO3Na+: 304.9784; found: 304.9783.
1b (818 mg) was obtained in 70% yield as a light yellow liquid. 1H
NMR (400 MHz, CDCl3) δ 7.32−7.26 (m, 2H), 6.97−6.88 (m, 2H),
5.21−5.10 (m, 2H), 4.72 (d, J = 8.6 Hz, 1H), 4.62 (d, J = 8.6 Hz,
1H), 3.82 (s, 3H), 1.71 (s, J = 1.5, 0.8 Hz, 3H). 13C NMR (100 MHz,
CDCl3) δ 160.07, 154.25, 143.08, 130.24, 126.70, 114.32, 113.84,
D
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SI-6: To a solution of the respective hydroxy phenyl ketone SI-5
(1.0 equiv) in THF (20 mL) was added isopropenylmagnesium
bromide (1.0 M in THF, 2.5 equiv) at 0 °C. The reaction was stirred
under a N2 atmosphere at room temperature for 2 h. The reaction
mixture was then quenched with saturated aqueous NH4Cl (5 mL),
and extracted with EtOAc (3 × 5 mL). The organic layer was then
dried over Na2SO4 and concentrated in vacuo to yield a yellow liquid.
The products were used in the next step without further purification.
3: To a solution of diol SI-6 (1.0 equiv) and pyridine (4.0 equiv) in
CH2Cl2 (20 mL) was added triphosgene (0.5 equiv, 1.0 M in
CH2Cl2) at 0 °C. The reaction was stirred under a N2 atmosphere at
room temperature for 2 h. The reaction mixture was then quenched
with saturated aqueous NH4Cl (5 mL), and extracted with CH2Cl2 (3
× 5 mL). The combined organic layers were dried over anhydrous
Na2SO4, filtered, and concentrated. The residue was purified by flash
chromatography on silica (PE:EA = 8:1) to afford the corresponding
carbonates 3. The characterizations of unreported substrates are as
following:
6.85 (d, J = 8.3 Hz, 2H), 6.08 (s, 1H), 5.50 (s, 1H), 5.33 (d, J = 1.4
Hz, 1H), 2.22 (s, 3H), 1.76 (s, 3H). 13C NMR (126 MHz, CDCl3) δ
154.09, 144.39, 138.08, 133.78, 132.28, 129.02, 128.70, 128.17,
127.47, 126.06, 114.01, 92.19, 84.62, 21.07, 19.69. HRMS (ESI+,
MeOH): [M + Na]+ calcd for C19H18O3Na+: 317.1148, found:
317.1149. HPLC conditions: (Chiralpak AS-H, i-PrOH/hexane = 20/
80, flow rate = 1.0 mL/min, λ = 254 nm).
General Procedure for the Synthesis of Highly Function-
alized δ-Lactones 2a−2j. A screw-capped vial was charged with the
cyclic vinyl carbonate 1 (0.1 mmol, 1.0 equiv), Pd(OAc)2 precatalyst
(1.3 mg, 6.0 mol %), DPPP (4.1 mg, 10.0 mol %), and CH3CN (2
mL). The reaction was stirred under a carbon monoxide atmosphere
at 45 °C for 6 h. A balloon was used to simulate respiratory air
movements and expired breaths by emptying the balloon. The
required carbon monoxide in the reaction process was under balloon
pressure. The reaction system should be filled with a gas of CO after
fully degassed. After reaction was completed, the excess gases should
be removed in a hood to prevent the escape of carbon monoxide. The
reaction mixture was purified by flash column chromatography on
silica gel (PE:EA = 4:1) to afford the corresponding lactones.
2a (16.0 mg) was obtained in 85% yield as a light yellow liquid. 1H
NMR (400 MHz, CDCl3) δ 7.41−7.36 (m, 2H), 7.33 (m, J = 5.1, 3.7
Hz, 1H), 7.19−7.16 (m, 2H), 5.00 (m, J = 2.3, 0.5 Hz, 2H), 3.16 (d, J
= 0.9 Hz, 2H), 1.77−1.73 (m, 3H). 13C NMR (100 MHz, CDCl3) δ
170.01, 136.59, 128.81, 128.77, 128.64, 127.92, 126.08, 72.14, 36.14,
3a (1.1 g) was obtained in 72% yield as a white solid. [α]2D5 = 93 (c
1
= 0.4, CHCl3). H NMR (300 MHz, CDCl3) δ 7.17−7.06 (m, 6H),
7.01−6.95 (m, 2H), 6.92 (m, J = 8.0, 1.4 Hz, 2H), 6.11 (s, 1H), 5.54
(s, 1H), 5.37 (d, J = 1.4 Hz, 1H), 1.77 (d, J = 0.6 Hz, 3H). 13C NMR
(75 MHz, CDCl3) δ 154.04, 144.17, 135.30, 133.67, 129.06, 128.27,
128.20, 128.04, 127.37, 126.08, 114.23, 92.13, 84.53, 19.75. HRMS
(ESI+, MeOH): [M + Na]+ calcd for C18H16O3Na+: 303.0992, found:
303.0989. HPLC conditions: (Chiralpak OD-H, i-PrOH/hexane = 5/
95, flow rate = 1.0 mL/min, λ = 254 nm).
+
19.07. HRMS (ESI+, MeOH): [M + H]+ calcd for C12H13O2 :
211.0730, found: 211.0731.
2b (18.7 mg) was obtained in 86% yield as a light yellow liquid. 1H
NMR (500 MHz, CDCl3) δ 7.12−7.08 (m, 2H), 6.95−6.89 (m, 2H),
4.96 (m, J = 4.0, 2.1 Hz, 2H), 3.82 (s,3H), 3.14 (d, J = 0.9 Hz, 2H),
1.75 (s, 3H). 13C NMR (125 MHz, CDCl3) δ 170.10, 159.29, 129.83,
128.76, 128.39, 125.48, 114.22, 72.24, 55.45, 36.18, 19.08. HRMS
(ESI+, MeOH): [M + Na]+ calcd for C13H14O3Na+: 241.0835, found:
241.0833.
3b (1.1 g) was obtained in 77% yield as a light yellow liquid. [α]D25
= 189 (c = 0.4, CHCl3). 1H NMR (300 MHz, CDCl3) δ 7.45 (m, J =
5.0, 2.9 Hz, 2H), 7.41−7.38 (m, 2H), 7.29−7.24 (m, 4H), 7.13−7.07
(m, 2H), 5.35 (d, J = 1.4 Hz, 1H), 5.28−5.22 (m, 2H), 2.51 (m, J =
14.9, 2.8 Hz, 1H), 2.35 (m, J = 15.0, 10.4 Hz, 1H), 1.75 (s, 3H). 13C
NMR (75 MHz, CDCl3) δ 153.77, 143.61, 136.09, 135.37, 129.18,
129.09, 128.95, 128.77, 127.22, 125.99, 113.93, 90.65, 83.78, 38.51,
19.54. HRMS (ESI+, MeOH): [M + Na]+ calcd for C19H18O3Na+:
317.1148, found: 317.1146. HPLC conditions: (Chiralpak AS-H, i-
PrOH/hexane = 20/80, flow rate = 1.0 mL/min, λ = 254 nm).
3c (1.1 g) was obtained in 71% yield as a light yellow liquid. [α]D25
= 33 (c = 0.4, CHCl3). 1H NMR (500 MHz, CDCl3) δ 7.23−7.18 (m,
1H), 7.17−7.13 (m, 2H), 7.11−7.07 (m, 2H), 6.92 (m, J = 8.0, 6.1
Hz, 4H), 6.09 (s, 1H), 5.53 (s, 1H), 5.37 (d, J = 1.4 Hz, 1H), 1.76 (d,
J = 0.6 Hz, 3H). 13C NMR (126 MHz, CDCl3) δ 153.68, 143.90,
134.43, 134.09, 133.46, 129.37, 128.46, 128.26, 127.60, 127.28,
114.61, 91.65, 84.36, 19.61. HRMS (ESI+, MeOH): [M + Na]+ calcd
for C18H15ClO3Na+: 337.0602, found: 337.0605. HPLC conditions:
(Chiralpak OD-H, i-PrOH/hexane = 5/95, flow rate = 1.0 mL/min, λ
= 254 nm).
2c (16.1 mg) was obtained in 80% yield as a light yellow liquid. 1H
NMR (500 MHz, CDCl3) δ 7.19 (d, J = 7.9 Hz, 2H), 7.07 (d, J = 8.0
Hz, 2H), 4.97 (m, J = 3.9, 2.0 Hz, 2H), 3.14 (d, J = 0.7 Hz, 2H), 2.37
(s, 3H), 1.75 (s, 3H). 13C NMR (75 MHz, CDCl3) δ 170.15, 137.74,
133.55, 129.44, 128.65, 128.52, 125.64, 72.22, 36.16, 21.33, 19.09.
HRMS (ESI+, MeOH): [M + Na]+ calcd for C13H14O2Na+:
225.0886, found: 225.0886.
2d (22.2 mg) was obtained in 91% yield as a white solid. 1H NMR
(300 MHz, CDCl3) δ 7.40 (d, J = 8.4 Hz, 2H), 7.11 (d, J = 8.5 Hz,
2H), 4.99 (d, J = 1.8 Hz, 2H), 3.15 (d, J = 0.9 Hz, 2H), 1.77 (s, 3H),
1.33 (s, 9H). 13C NMR (101 MHz, CDCl3) δ 170.18, 150.91, 133.52,
128.63, 128.31, 125.69, 125.63, 72.20, 36.22, 34.75, 31.42, 19.15.
HRMS (ESI+, MeOH): [M + Na]+ calcd for C16H20O2Na+:
267.1356, found: 267.1357.
3d (995 mg) was obtained in 67% yield as a light yellow liquid.
[α]2D5 = 40 (c = 0.4, CHCl3). 1H NMR (500 MHz, CDCl3) δ 7.18 (d,
J = 7.2 Hz, 1H), 7.14 (m, J = 8.1, 6.5 Hz, 2H), 6.96 (m, J = 5.4, 3.5
Hz, 2H), 6.92 (m, J = 12.0, 4.9 Hz, 2H), 6.80 (t, J = 8.7 Hz, 2H), 6.10
(s, 1H), 5.53 (s, 1H), 5.37 (d, J = 1.4 Hz, 1H), 1.77 (d, J = 0.6 Hz,
3H). 13C NMR (126 MHz, CDCl3) δ 153.78, 144.10, 133.61, 129.26,
128.40, 128.10, 128.03, 127.28, 115.16, 114.99, 114.48, 91.75, 84.43,
19.66. HRMS (ESI+, MeOH): [M + Na]+ calcd for C18H15FO3Na+:
321.0897, found: 321.0898. HPLC conditions: (Chiralpak OD-H, i-
PrOH/hexane = 5/95, flow rate = 1.0 mL/min, λ = 254 nm).
3e (1.1 g) was obtained in 69% yield as a light yellow liquid. [α]D25
2e (16.6 mg) was obtained in 75% yield as a light yellow liquid. 1H
NMR (500 MHz, CDCl3) δ 7.38−7.35 (m, 2H), 7.13−7.10 (m, 2H),
4.98−4.93 (m, 2H), 3.15 (m, J = 3.3, 2.3 Hz, 2H), 1.76−1.72 (m,
3H). 13C NMR (126 MHz, CDCl3) δ 169.62, 135.00, 133.97, 130.00,
129.07, 127.88, 127.01, 71.82, 36.16, 19.07. HRMS (ESI+, MeOH):
[M + Na]+ calcd for C12H11ClO2Na+: 245.0340, found: 245.0341.
1
2f (1.6 mg) was obtained in 71% yield as a light yellow liquid. H
NMR (500 MHz, CDCl3) δ 7.18−7.10 (m, 2H), 7.08 (t, J = 8.7 Hz,
2H), 4.96 (m, J = 4.2, 2.3 Hz, 2H), 3.15 (d, J = 0.9 Hz, 2H), 1.75−
1.68 (m, 3H). 13C NMR (75 MHz, CDCl3) δ 169.82, 163.98, 160.71,
132.46, 130.42, 130.32, 127.87, 126.55, 115.97, 115.68, 72.02, 36.08,
19.05. HRMS (ESI+, MeOH): [M + Na]+ calcd for C12H11FO2Na+:
229.0635, found: 229.0641.
1
= 52 (c = 0.4, CHCl3). H NMR (500 MHz, CDCl3) δ 7.14 (m, J =
8.5, 7.0 Hz, 3H), 6.94−6.91 (m, 2H), 6.89−6.85 (m, 2H), 6.64−6.59
(m, 2H), 6.07 (s, 1H), 5.49 (s, 1H), 5.33 (d, J = 1.4 Hz, 1H), 3.70 (s,
3H), 1.76 (s, 3H). 13C NMR (126 MHz, CDCl3) δ 159.46, 154.05,
144.37, 133.74, 129.03, 128.20, 127.44, 127.40, 127.21, 114.02,
113.38, 92.05, 84.61, 55.29, 19.66. HRMS (ESI+, MeOH): [M +
Na]+ calcd for C19H18O4Na+: 333.1097, found: 333.1095. HPLC
conditions: (Chiralpak AS-H, i-PrOH/hexane = 20/80, flow rate =
1.0 mL/min, λ = 254 nm).
2g (20.1 mg) was obtained in 76% yield as a light yellow liquid. 1H
NMR (400 MHz, CDCl3) δ 7.55−7.44 (m, 2H), 7.08−6.97 (m, 2H),
4.97−4.92 (m, 2H), 3.15 (d, J = 0.9 Hz, 2H), 1.74 (s, 3H). 13C NMR
(126 MHz, CDCl3) δ 169.60, 135.49, 132.03, 130.31, 127.90, 127.04,
122.07, 71.75, 36.17, 19.08. HRMS (ESI+, MeOH): [M + Na]+ calcd
for C12H11BrO2Na+: 288.9835, found: 288.9827.
3f (882 mg) was obtained in 60% yield as a light yellow liquid.
[α]2D5 = 30 (c = 0.4, CHCl3). 1H NMR (500 MHz, CDCl3) δ 7.17 (m,
J = 10.4, 4.1 Hz, 1H), 7.12 (t, J = 7.4 Hz, 2H), 6.94−6.89 (m, 4H),
2h (14.2 mg) was obtained in 71% yield as a light yellow liquid. 1H
NMR (300 MHz, CDCl3) δ 7.26 (t, J = 4.0 Hz, 1H), 7.13 (d, J = 7.4
Hz, 1H), 6.97 (d, J = 7.5 Hz, 2H), 4.98 (m, J = 4.1, 2.3 Hz, 2H), 3.15
E
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(d, J = 0.9 Hz, 2H), 2.37 (s, 3H), 1.75 (s, 3H). 13C NMR (75 MHz,
CDCl3) δ 170.11, 138.45, 136.53, 129.23, 128.86, 128.64, 125.78,
125.72, 72.21, 36.12, 21.55, 19.10. HRMS (ESI+, MeOH): [M +
Na]+ calcd for C13H14O2Na+: 225.0886, found: 225.0886.
4d (22.5 mg) was obtained in 80% yield as a light yellow liquid.
[α]2D5 = 82 (c = 0.4, CHCl3). H NMR (300 MHz, CDCl3) δ 7.33−
1
7.22 (m, 5H), 7.07−6.97 (m, 4H), 6.06−5.96 (m, 1H), 3.34−3.05
(m, 2H), 1.80 (s, 3H). 13C NMR (75 MHz, CDCl3) δ 169.43, 163.27,
160.81, 137.27, 132.80, 132.77, 130.71, 130.69, 130.63, 128.84,
128.78, 127.32, 115.61, 115.40, 84.72, 36.19, 19.27. HRMS (ESI+,
MeOH): [M + Na]+ calcd for C18H15FO2Na+: 305.0948, found:
305.0947. HPLC conditions: (Chiralpak OD-H, i-PrOH/hexane = 5/
95, flow rate = 1.0 mL/min, λ = 254 nm).
2i (14.3 mg) was obtained in 66% yield as a light yellow liquid. 1H
NMR (400 MHz, CDCl3) δ 7.33−7.28 (m, 1H), 7.06 (m, J = 7.4, 1.8
Hz, 1H), 6.99−6.90 (m, 2H), 4.93 (s, 2H), 3.80 (s, 3H), 3.16 (d, J =
0.9 Hz, 2H), 1.68 (s, 3H). 13C NMR (126 MHz, CDCl3) δ 170.57,
157.17, 130.91, 129.50, 127.02, 126.90, 125.33, 120.74, 111.09, 71.45,
55.52, 36.38, 19.10. HRMS (ESI+, MeOH): [M + Na]+ calcd for
C13H14O3Na+: 241.0835, found: 241.0831.
4e (25.2 mg) was obtained in 86% yield as a light yellow liquid.
[α]2D5 = −77 (c = 0.4, CHCl3). H NMR (300 MHz, CDCl3) δ 7.30
1
2j (16.5 mg) was obtained in 76% yield as a light yellow liquid. 1H
NMR (300 MHz, CDCl3) δ 7.33−7.27 (m, 1H), 6.89−6.84 (m, 1H),
6.78−6.69 (m, 2H), 4.98 (d, J = 1.9 Hz, 2H), 3.82 (s, 3H), 3.15 (d, J
= 0.9 Hz, 2H), 1.76 (s, 3H). 13C NMR (75 MHz, CDCl3) δ 170.01,
159.80, 137.97, 129.84, 128.67, 126.16, 120.99, 114.52, 113.12, 72.09,
55.42, 36.10, 19.11. HRMS (ESI+, MeOH): [M + Na]+ calcd for
C13H14O3Na+: 241.0835, found: 241.0834.
(m, J = 4.7, 2.3 Hz, 3H), 7.27−7.21 (m, 2H), 7.04−6.99 (m, 2H),
6.86−6.81 (m, 2H), 6.04 (s, 1H), 3.78 (s, 3H), 3.14 (t, J = 15.7 Hz,
2H), 1.82 (s, 3H). 13C NMR (75 MHz, CDCl3) δ 170.19, 159.05,
137.67, 131.26, 130.29, 129.25, 128.88, 127.52, 126.63, 114.04, 84.90,
55.35, 36.53, 19.53. HRMS (ESI+, MeOH): [M + Na]+ calcd for
C19H18O3Na+: 317.1148, found: 317.1147. HPLC conditions:
(Chiralpak OD-H, i-PrOH/hexane = 20/80, flow rate = 1.0 mL/
min, λ = 254 nm).
General Procedure for the Synthesis of Highly Function-
alized δ-Lactones 4a−4h. A screw-capped vial was charged with
the cyclic vinyl carbonate 3 (0.1 mmol, 1.0 equiv), Pd(OAc)2
precatalyst (1.3 mg, 6.0 mol %), DPPP (4.1 mg, 10.0 mol %), and
CH3CN (2 mL). The reaction was stirred under a CO atmosphere at
80 °C for 12 h. A balloon was used to simulate respiratory air
movements and expired breaths by emptying the balloon. The
required carbon monoxide in the reaction process was under balloon
pressure. The reaction system should be filled with a gas of CO after
fully degassed. After reaction was completed, the excess gases should
be removed in a hood to prevent the escape of carbon monoxide. The
reaction mixture was purified by flash column chromatography on
silica gel (PE:EA = 4:1) to afford the corresponding lactones.
4a (21.1 mg) was obtained in 80% yield as a light yellow liquid. [α]
= −71 (c = 0.45, CHCl3). 1H NMR (300 MHz, CDCl3) δ 7.35−7.31
(m, 2H), 7.31−7.27 (m, 4H), 7.26−7.22 (m, 2H), 7.12−7.07 (m,
2H), 6.07 (s, 1H), 3.19 (d, J = 10.5 Hz, 2H), 1.82 (s, 3H). 13C NMR
(126 MHz, CDCl3) δ 169.99, 137.64, 137.16, 131.86, 129.16, 128.92,
128.91, 128.65, 127.78, 127.56, 127.18, 84.91, 36.55, 19.52. HRMS
(ESI+, MeOH): [M + Na]+ calcd for C18H16O2Na+: 287.1043, found:
287.1038. HPLC conditions: (Chiralpak OD-H, i-PrOH/hexane = 5/
95, flow rate = 1.0 mL/min, λ = 254 nm).
4f (23.6 mg) was obtained in 85% yield as a light yellow liquid.
[α]2D5 = −62 (c = 0.4, CHCl3). H NMR (300 MHz, CDCl3) δ 7.30
1
(m, J = 4.6, 2.3 Hz, 3H), 7.24 (m, J = 7.2, 2.7 Hz, 2H), 7.12 (d, J = 7.9
Hz, 2H), 6.99 (d, J = 8.1 Hz, 2H), 6.06 (s, 1H), 3.27−3.07 (m, 2H),
2.32 (s, 3H), 1.82 (s, 3H). 13C NMR (126 MHz, CDCl3) δ 170.05,
137.77, 137.55, 134.17, 131.77, 129.35, 129.02, 128.87, 128.85,
127.56, 126.82, 84.94, 36.59, 21.27, 19.51. HRMS (ESI+, MeOH):
+
[M + H]+ calcd for C19H19O2 : 279.1380, found: 279.1381. HPLC
conditions: (Chiralpak OD-H, i-PrOH/hexane = 20/80, flow rate =
1.0 mL/min, λ = 254 nm).
General Procedure for the Synthesis of Highly Function-
alized δ-Lactones 6a−6h. A screw-capped vial was charged with
the vinyloxazolidinone 5 (0.1 mmol, 1.0 equiv), Pd(OAc)2 precatalyst
(1.3 mg, 6.0 mol %), L1 (5.4 mg, 10.0 mol %), and CH3CN (2 mL).
A balloon was used to simulate respiratory air movements and expired
breaths by emptying the balloon. The required carbon monoxide in
the reaction process was under balloon pressure. The reaction system
should be filled with a gas of CO after fully degassed. After reaction
was completed, the excess gases should be removed in a hood to
prevent the escape of carbon monoxide. The reaction was stirred
under a CO atmosphere at rt for 6 h. The reaction mixture was
purified by flash column chromatography on silica gel (PE:EA = 4:1)
to afford the corresponding lactams.
ent-4a (21.6 mg) was obtained in 82% yield as a light yellow liquid.
[α] = 110 (c = 0.4, CHCl3). 1H NMR (300 MHz, CDCl3) δ 7.32 (m,
J = 6.4, 1.5 Hz, 3H), 7.30−7.27 (m, 3H), 7.26−7.21 (m, 2H), 7.11−
7.08 (m, 2H), 6.07 (s, 1H), 3.29−3.09 (m, 2H), 1.82 (s, 3H). 13C
NMR (75 MHz, CDCl3) δ 170.06, 137.55, 137.09, 131.74, 129.13,
128.91, 128.89, 128.63, 127.76, 127.54, 127.18, 84.85, 36.53, 19.52.
HRMS (ESI+, MeOH): [M + Na]+ calcd for C18H16O2Na+:
287.1043, found: 287.1042. HPLC conditions: (Chiralpak OD-H, i-
PrOH/hexane = 5/95, flow rate = 1.0 mL/min, λ = 254 nm).
4b (21.9 mg) was obtained in 79% yield as a light yellow liquid. [α]
= −99 (c = 0.4, CHCl3). 1H NMR (300 MHz, CDCl3) δ 7.45 (m, J =
7.9, 6.6 Hz, 2H), 7.40−7.33 (m, 1H), 7.28 (m, J = 6.0, 4.2 Hz, 5H),
7.17 (m, J = 6.8, 2.6 Hz, 2H), 5.44 (s, 1H), 3.09 (m, J = 14.1, 4.6 Hz,
1H), 2.75 (m, J = 14.1, 4.4 Hz, 1H), 2.62 (d, J = 21.1 Hz, 1H), 1.95
(d, J = 21.2 Hz, 1H), 1.57 (s, 3H). 13C NMR (75 MHz, CDCl3) δ
170.17, 137.04, 135.21, 130.66, 130.20, 129.41, 128.88, 128.46,
127.91, 127.23, 127.07, 83.52, 39.89, 35.29, 19.20. HRMS (ESI+,
6a was obtained as a yellow liquid (22.1 mg, 77% yield). 1H NMR
(300 MHz, CDCl3)) δ 7.28 (d, J = 7.8 Hz, 2H), 7.18 (d, J = 7.9 Hz,
2H), 6.13−5.92 (m, 1H), 4.62 (m, J = 3.1, 1.4 Hz, 2H), 3.26 (d, J =
3.5 Hz, 2H), 2.37 (s, 3H), 1.57 (s, 9H). 13C NMR (75 MHz, CDCl3)
δ 168.61, 152.25, 138.00, 134.53, 133.08, 129.39, 125.04, 117.53,
83.54, 77.44, 77.22, 77.02, 76.59, 48.56, 35.65, 28.03, 21.12. HRMS
(ESI+, MeOH): [M + Na]+ calcd for C17H21NO3Na+: 310.1414,
found: 310.1407.
6b was obtained as a yellow liquid (24.8 mg, 82% yield). 1H NMR
(300 MHz, CDCl3) δ 7.32 (d, J = 8.8 Hz, 2H), 6.96−6.85 (m, 2H),
5.98 (m, J = 4.0, 1.4 Hz, 1H), 4.61 (m, J = 3.1, 1.4 Hz, 2H), 3.83 (s,
3H), 3.25 (m, J = 4.1, 3.1 Hz, 2H). 1.57 (s, 9H). 13C NMR (75 MHz,
CDCl3) δ 168.68, 159.49, 152.27, 132.65, 129.90, 126.35, 116.67,
114.05, 83.54, 77.46, 77.03, 76.61, 55.34, 48.56, 35.64, 28.03. HRMS
(ESI+, MeOH): [M + Na]+ calcd for C17H21NO4Na+: 326.1363,
found: 326.1364.
+
MeOH): [M + H]+ calcd for C19H19O2 : 279.1380, found: 297.1381.
6c was obtained as a yellow liquid (24.6 mg, 81% yield). 1H NMR
(300 MHz, CDCl3) δ 7.37−7.28 (m, 4H), 6.18−6.02 (m, 1H), 4.60
(m, J = 3.2, 1.4 Hz, 2H), 3.27 (m, J = 4.0, 3.2 Hz, 2H), 1.57 (s, 9H).
13C NMR (75 MHz, CDCl3) δ 168.16, 152.21, 135.80, 133.98,
HPLC conditions: (Chiralpak AS-H, i-PrOH/hexane = 20/80, flow
rate = 1.0 mL/min, λ = 254 nm).
4c (24.4 mg) was obtained in 82% yield as a light yellow liquid. [α]
1
= −31 (c = 0.4, CHCl3). H NMR (300 MHz, CDCl3) δ 7.33−7.25
132.27, 128.90, 126.47, 119.07, 83.75, 77.46, 77.03, 76.61, 48.32,
35.63, 28.02. HRMS (ESI+, MeOH): [M + Na]+ calcd for
C16H18NO3ClNa+: 330.0867, found: 330.0865.
(m, 5H), 7.21 (m, J = 6.8, 2.8 Hz, 2H), 7.04−6.99 (m, 2H), 6.01 (s,
1H), 3.29−3.10 (m, 2H), 1.80 (s, 3H). 13C NMR (75 MHz, CDCl3)
δ 169.60, 137.32, 135.48, 133.80, 130.74, 130.51, 129.11, 129.02,
128.94, 127.84, 127.50, 84.72, 36.40, 19.51. HRMS (ESI+, MeOH):
[M + Na]+ calcd for C18H15ClO2Na+: 321.0653, found: 321.0653.
HPLC conditions: (Chiralpak OD-H, i-PrOH/hexane = 5/95, flow
rate = 1.0 mL/min, λ = 254 nm).
6d was obtained as a yellow liquid (25.0 mg, 86% yield). 1H NMR
(300 MHz, CDCl3) δ 7.41−7.30 (m, 2H), 7.06 (t, J = 8.6 Hz, 2H),
6.11−5.94 (m, 1H), 4.60 (m, J = 3.2, 1.4 Hz, 2H), 3.26 (t, J = 3.5 Hz,
2H), 1.57 (s, 9H). 13C NMR (75 MHz, CDCl3) δ 168.26, 164.20,
160.92, 152.24, 133.58, 133.53, 132.39, 126.98, 126.87, 118.44,
F
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115.79, 115.50, 83.69, 77.46, 77.03, 76.61, 48.54, 35.61, 28.02. HRMS
(ESI+, MeOH): [M + Na]+ calcd for C16H18NO3FNa+: 314.1163,
found: 314.1163.
CDCl3) δ 169.10, 151.76, 137.18, 135.36, 129.14, 128.37, 128.05,
125.68, 83.36, 77.44, 77.22, 77.02, 76.59, 51.10, 41.45, 28.02, 21.18,
18.96. HRMS (ESI+, MeOH): [M + Na]+ calcd for C18H23NO3Na+:
324.1570, found: 324.1570.
6e was obtained as a yellow liquid (22.6 mg, 79% yield). 1H NMR
(300 MHz, CDCl3) δ 7.37−7.22 (m, 2H), 7.19−7.12 (m, 2H), 6.07
(m, J = 4.0, 1.4 Hz, 1H), 4.63 (m, J = 3.1, 1.4 Hz, 2H), 3.27 (q, J = 3.4
Hz, 2H), 2.38 (s, 3H), 1.57 (s, 9H). 13C NMR (75 MHz, CDCl3) δ
168.56, 152.31, 138.38, 137.40, 133.36, 128.85, 128.61, 125.94,
122.29, 118.21, 83.59, 77.44, 77.22, 77.02, 76.60, 48.57, 35.69, 28.04,
21.49. HRMS (ESI+, MeOH): [M + Na]+ calcd for C17H21NO3Na+:
310.1414, found: 310.1416.
11 was obtained as a yellow liquid (22.2 mg, 61% yield). 1H NMR
(400 MHz, Chloroform-d) δ 8.48−8.35 (m, 2H), 8.34−8.24 (m, 2H),
7.48−7.37 (m, 5H), 6.07 (m, J = 3.9, 2.4, 1.5 Hz, 1H), 4.94 (m, J =
3.4, 1.6 Hz, 2H), 3.25 (d, J = 3.7 Hz, 2H). 13C NMR (101 MHz,
CDCl3) δ 167.63, 150.72, 144.03, 136.51, 132.48, 130.25, 128.87,
128.61, 125.22, 123.88, 117.77, 77.26, 76.94, 76.62, 48.94, 34.45.
HRMS (ESI+, MeOH): [M + Na]+ calcd for C17H14SN2O5Na+:
381.0516, found: 381.0518.
1
6f was obtained as a yellow liquid (22.1 mg, 73% yield). H NMR
1
12 was obtained as a white solid (19.4 mg, 62% yield). H NMR
(300 MHz, CDCl3) δ 7.32 (d, J = 7.9 Hz, 1H), 7.05−6.83 (m, 3H),
6.16−5.98 (m, 1H), 4.63 (m, J = 3.1, 1.4 Hz, 2H), 3.85 (s, 3H), 3.28
(q, J = 3.4 Hz, 2H), 1.58 (s, 9H). 13C NMR (75 MHz, CDCl3) δ
168.48, 159.85, 152.19, 138.92, 133.21, 129.77, 118.73, 117.67,
113.27, 111.28, 83.62, 77.47, 77.23, 76.62, 76.54, 55.33, 48.56, 35.66,
28.03. HRMS (ESI+, MeOH): [M + Na]+ calcd for C17H21NO4Na+:
326.1363, found: 326.1364.
(300 MHz, Chloroform-d) δ 8.13−7.81 (m, 2H), 7.79−7.44 (m, 4H),
7.44−7.33 (m, 4H), 6.13−5.91 (m, 1H), 4.91 (m, J = 3.5, 1.6 Hz,
2H), 3.21 (q, J = 3.6 Hz, 2H). 13C NMR (75 MHz, CDCl3) δ 167.47,
138.63, 136.88, 134.01, 132.63, 128.86, 128.82, 128.78, 128.48,
125.32, 117.97, 77.44, 77.02, 76.59, 48.89, 34.63. HRMS (ESI+,
MeOH): [M + Na]+ calcd for C17H15SNO3Na+: 336.0665, found:
336.0666.
6g was obtained as a yellow liquid (21.8 mg, 76% yield). 1H NMR
(300 MHz, CDCl3) δ 7.25−7.08 (m, 4H), 5.68 (m, J = 3.8, 1.4 Hz,
1H), 4.40 (m, J = 3.0, 1.4 Hz, 2H), 3.26 (q, J = 3.3 Hz, 2H), 2.30 (s,
3H), 1.54 (s, 9H). 13C NMR (75 MHz, CDCl3) δ 168.72, 151.81,
138.55, 135.45, 135.05, 130.47, 128.62, 128.02, 125.94, 120.71, 83.53,
77.44, 77.22, 77.02, 76.60, 50.17, 35.68, 28.01, 19.84. HRMS (ESI+,
MeOH): [M + Na]+ calcd for C17H21NO3Na+: 310.1414, found:
310.1416.
ASSOCIATED CONTENT
* Supporting Information
The Supporting Information is available free of charge at
https://pubs.acs.org/doi/10.1021/acs.organomet.0c00646.
■
sı
Crystallography of 2d, 3a, and 11, and NMR spectra of
1−6 (PDF)
6h was obtained as a yellow liquid (22.3 mg, 82% yield). 1H NMR
(300 MHz, CDCl3) δ 7.47−7.29 (m, 5H), 6.16−6.01 (m, 1H), 4.65
(m, J = 3.1, 1.4 Hz, 2H), 3.28 (m, J = 4.2, 3.2 Hz, 2H), 1.57 (s, 9H).
13C NMR (75 MHz, CDCl3) δ 168.51, 152.21, 137.41, 133.29,
128.73, 128.11, 125.19, 118.45, 83.61, 77.44, 77.22, 77.02, 76.60,
48.53, 35.68, 28.03. HRMS (ESI+, MeOH): [M + Na]+ calcd for
C16H19NO3Na+: 296.1257, found: 296.1255.
General Procedure G: Gram-Scale Synthesis and Derivati-
zation Reactions. A screw-capped vial was charged with the cyclic
vinyl carbonate 1a (4.9 mmol, 1.0 g), Pd(OAc)2 precatalyst (65 mg,
0.3 mol), DPPP (201 mg, 0.49), and CH3CN (20 mL). The reaction
was stirred under a CO atmosphere at 45 °C for 6 h. A balloon was
used to simulate respiratory air movements and expired breaths by
emptying the balloon. The required carbon monoxide in the reaction
process was under balloon pressure. The reaction system should be
filled with a gas of CO after fully degassed. After reaction was
completed, the excess gases should be removed in a hood to prevent
the escape of carbon monoxide. The reaction mixture was purified by
flash column chromatography on silica gel (PE:EA = 4:1) to afford
the corresponding lactones 2a in 82% yield (755 mg).
Accession Codes
CCDC 1911274, 1911275, and 1917984 contain the
supplementary crystallographic data for this paper. These
data can be obtained free of charge via www.ccdc.cam.ac.uk/
data_request/cif, or by emailing data_request@ccdc.cam.ac.
uk, or by contacting The Cambridge Crystallographic Data
Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: +44
1223 336033.
AUTHOR INFORMATION
Corresponding Authors
■
Jianxian Gong − State Key Laboratory of Chemical
Oncogenomics, Key Laboratory of Chemical Genomics, Peking
University Shenzhen Graduate School, Shenzhen 518055,
China; orcid.org/0000-0003-4331-0976; Email: gongjx@
pku.edu.cn
Zhen Yang − State Key Laboratory of Chemical Oncogenomics,
Key Laboratory of Chemical Genomics, Peking University
Shenzhen Graduate School, Shenzhen 518055, China; Key
Laboratory of Bioorganic Chemistry and Molecular Engineering
of Ministry of Education and Beijing National Laboratory for
Molecular Science (BNLMS), and Peking-Tsinghua Center for
Life Sciences, Peking University, Beijing 100871, China;
orcid.org/0000-0001-8036-934X; Email: zyang@
pku.edu.cn
A screw-capped vial was charged with the vinyloxazolidinone 7 (0.1
mmol, 1.0 equiv), Pd(OAc)2 precatalyst (1.3 mg, 6.0 mol %), L1 (5.4
mg, 10.0 mol %), and CH3CN (2 mL). The reaction was stirred under
a CO atmosphere at rt for 6 h. A balloon was used to simulate
respiratory air movements and expired breaths by emptying the
balloon. The required carbon monoxide in the reaction process was
under balloon pressure. The reaction system should be filled with a
gas of CO after fully degassed. After reaction was completed, the
excess gases should be removed in a hood to prevent the escape of
carbon monoxide. The reaction mixture was purified by flash column
chromatography on silica gel (PE:EA = 4:1) to afford the
corresponding lactams.
Authors
1
Linlin Shi − State Key Laboratory of Chemical Oncogenomics,
Key Laboratory of Chemical Genomics, Peking University
Shenzhen Graduate School, Shenzhen 518055, China; College
of Chemistry, Zhengzhou University, Zhengzhou, Henan
450001, China
Yingdong He − State Key Laboratory of Chemical
Oncogenomics, Key Laboratory of Chemical Genomics, Peking
University Shenzhen Graduate School, Shenzhen 518055,
China
8 was obtained as a yellow liquid (18.6 mg, 65% yield). H NMR
(300 MHz, CDCl3) δ 7.46−7.28 (m, 3H), 7.26−7.10 (m, 2H), 4.56−
4.30 (m, 2H), 3.32−2.94 (m, 2H), 1.71 (d, J = 1.1 Hz, 3H), 1.55 (s,
9H). 13C NMR (75 MHz, CDCl3) δ 169.03, 151.79, 138.37, 128.50,
128.21, 127.45, 126.08, 83.45, 77.46, 77.24, 77.04, 76.61, 51.06, 41.45,
28.04, 18.96, 1.03. HRMS (ESI+, MeOH): [M + Na]+ calcd for
C17H21NO3Na+: 310.1414, found: 310.1413.
1
9 was obtained as a yellow liquid (18.1 mg, 60% yield). H NMR
(300 MHz, Chloroform-d) δ 7.22−7.16 (m, 2H), 7.14−7.05 (m, 2H),
4.41 (m, J = 2.7, 1.5 Hz, 2H), 3.17 (m, J = 2.7, 1.1 Hz, 2H), 2.37 (s,
3H), 1.70 (m, J = 1.8, 0.9 Hz, 3H), 1.54 (s, 9H). 13C NMR (75 MHz,
Complete contact information is available at:
G
https://dx.doi.org/10.1021/acs.organomet.0c00646
Organometallics XXXX, XXX, XXX−XXX

Organometallics
pubs.acs.org/Organometallics
Article
(12) Jevric, M.; Taylor, D. K.; Greatrex, B. W.; Tiekink, E. R. T.
DDQ induced oxidative cyclisations of 1,2-dihydronaptho[2,1-b]-
furans. Tetrahedron 2005, 61, 1885−1891.
https://pubs.acs.org/10.1021/acs.organomet.0c00646
Author Contributions
∥These authors contributed equally to this work.
(13) (a) Colquhoun, H. M.; Thompson, D. G.; Twigg, M. V.
Carbonylation; Plenum Press: New York, 1991; p 191. (b) Knight, J.
G.; Ainge, S. W.; Harm, A. M.; Harwood, S. J.; Maughan, H. I.;
Armour, D. R.; Hollinshead, D. M.; Jaxa-Chamiec, A. A.
Enantioselective Synthesis of 3,6-dihydro-1H-pyridin-2-ones: unex-
pected regioselectivity in the palladium-catalyzed decarboxylative
carbonylation of 5-vinyloxazolidin-2-ones. J. Am. Chem. Soc. 2000,
122, 2944−2945. (c) Knight, J. G.; Tchabanenko, K. Diastereospecific
carbonylation of π-allylpalladium complexes to give 3,6-disubstituted-
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Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
We are thankful for the financial support from the National
Science Foundation of China (Grant nos. 21772008,
21632002, 21572009, and U1606403), Guangdong Natural
Science Foundation (Grant nos. 2014A030312004 and
2016A030306011), Shenzhen Peacock Plan (KQTD2015-
071714043444), and Shenzhen Basic Research Program
(Grant nos. JCYJ2016033009562978 and JCYJ201602261-
05337556).
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Organometallics XXXX, XXX, XXX−XXX