Gold(I)-catalysed synthesis of cyclic sulfamidates: Current scope, stereochemistry and competing ene-allene cycloisomerisation

Article abstract of DOI:10.1016/j.tet.2014.11.058

Six-membered cyclic sulfamidates are prepared in high yields by treatment of allenic sulfamates with readily available Ph₃PAuNTf₂. The reaction enables formation of N-substituted quaternary centres in high yields. The relative stereo

Full text of DOI:10.1016/j.tet.2014.11.058

Tetrahedron 71 (2015) 727e737
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Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Gold(I)-catalysed synthesis of cyclic sulfamidates: current scope,
stereochemistry and competing ene-allene cycloisomerisation
Mari C.M. Higginbotham, Lorna Kennedy, Anita G. Lindsay, Andreas Troester,
*
Magnus W.P. Bebbington
School of EPS-Institute of Chemical Science, Heriot-Watt University, Riccarton, Edinburgh, EH14 4AS, UK
a r t i c l e i n f o
a b s t r a c t
Article history:
Six-membered cyclic sulfamidates are prepared in high yields by treatment of allenic sulfamates with
Received 15 September 2014
Received in revised form 13 November 2014
Accepted 24 November 2014
Available online 5 December 2014
readily available Ph3PAuNTf2. The reaction enables formation of N-substituted quaternary centres in high
yields. The relative stereochemistry has been unambiguously determined. A
p-rearrangement is faster
than hydroamination in the case of an allyl-substituted sulfamate and a mechanism is proposed for this
process.
Ó 2014 Elsevier Ltd. All rights reserved.
Keywords:
Gold catalysis
Sulfamidates
Hydroamination
Allenes
1. Introduction
A) Traditional 2-step approach:
O O
Cyclic sulfamidates are versatile intermediates for the synthesis
of substituted amines, and the development of their chemistry is of
ongoing and increasing interest.1
1. SOCl2, Et3N
S
OH NHR
O
NR
R2
2. NaIO4, cat. RuCl3
R1
R2
n
R1
n
They readily undergo SN2 reaction at the oxygen-bearing carbon
with a variety of heteroatoms and carbon nucleophiles including
stabilised enolates (Scheme 1). The traditional two-step route to
sulfamidates involves treatment of amino alcohols with thionyl
chloride to give an intermediate sulfamidite that is then subjected
to Ru-catalysed oxidation to the corresponding sulfamidate
(Scheme 2, A).1
n = 1, 2 or 3
B) Metal-catalysed C-H insertion
O O
S
SO2NH2
H
metal catalyst
O
O
NH
R2
oxidant
R1
R2
R1
C) Hydroamination (this work)
SO2NH2
O O
S
Au(I) complex
O
R2
O
NH
redox neutral
R1
R1
R2
Scheme 2. Synthetic approaches to sulfamidates.
The requirement for the strongly oxidising step limits the
functional group tolerance of this methoddalkenes and alkynes are
normally incompatible with these conditions. Notably, perhaps the
most self-evident approachddirect reaction of amino alcohols with
sulfuryl chloride (SO2Cl2) does not usually lead to sulfamidate
products, but instead to aziridines, or more commonly, to substrate
decomposition.1
Scheme 1. Reactivity of cyclic sulfamidates.
* Corresponding author. Tel.: þ44 (0)131451 8071; fax: þ44(0) 131 451 3180;
e-mail address: m.w.p.bebbington@hw.ac.uk (M.W.P. Bebbington).
http://dx.doi.org/10.1016/j.tet.2014.11.058
0040-4020/Ó 2014 Elsevier Ltd. All rights reserved.

728
M.C.M. Higginbotham et al. / Tetrahedron 71 (2015) 727e737
Table 1B
In recent years, a number of procedures have emerged for the
Sulfamate preparation via JohnsoneClaisen rearrangementa
preparation of this useful class of compounds via catalytic CeN
bond formation.2 This area has to-date been dominated by metal-
catalysed generation of a reactive nitrenoid from a linear sulfa-
mate precursor under oxidising conditions (Scheme 2, B). This
species can undergo insertion into an appropriately positioned
CeH bond, usually to form six-membered rings. Alternatively, ad-
dition to a pendant alkene gives fused aziridines. These approaches
have been successfully employed in a number of complex target
syntheses.3
Transition metal-catalysed hydroamination is an increasingly
useful method for the preparation of amines.4e8 Given the high
reactivity of allenes and the use of gold complexes to promote
hydroamination with unsaturated tosyl sulfonamides, we decided
to investigate the viability of gold-catalysed sulfamidate synthesis
using allenic sulfamates and recently reported the first results of
these studies (Scheme 2, C).9,10 We now wish to give a full account
of our work so far on this new route to cyclic sulfamidates, in-
cluding elucidation of and a tentative explanation for the unusual
diastereoselectivity found in the reaction of one of the substrates,
some substrates, which illustrate the current limitations of this
reaction and an unusual amidine synthesis that fully demonstrates
the sterically encumbered environment around the nitrogen atom
in the products.
Starting alcohol
R3
R4
H
R5
R6
4b
4c
4g
4h
4i
4j
4k
4l
4m
4n
4o
4q
n-C5H11
e(CH2)5e
H
H
H
H
H
Me
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
n-C3H7
n-C6H13
CH2-c-C6C11
(CH2)2OBn
CH2OBn
CH2OMe
i-C3H7
n-C4H9
Ph
H
Me
Me
a
For experimental details see Supplementary data.
2. Results and discussion
Table 2
Initial catalyst screen and controlsa
The allenic sulfamates used in this study were prepared by ei-
ther of two routes: (A) JohnsoneClaisen rearrangement11 of
substituted propargyl alcohols to give allenic esters, followed by
reduction and sulfamoylation12 (Table 1A, or B) Crabbe homolo-
gation13 of substituted homopropargyl alcohols then sulfamoyla-
tion (Table 1B).
O
O
5 mol% catalyst
DCM, r. t., 24 h
S
H2NSO2O
O
NH
3a
5a
Entry
Catalyst
Yield 5a/%
dr cis:trans
Table 1A
a
1
2
3
4
5
6
7
8
None
AgOTf
TfOH
0
0
0
74
99
48
43
82
NA
NA
NA
1.7:1
1.2:1
1:1
2:1
1:1
ꢀ
Sulfamate preparation via Crabbe homologation
(Ph3P)AuCl/AgOTf
(Ph3P)AuNTf2
IPrAuCl/AgOTf
(2,4-Di-tBuPhO)3PAuCI/AgOTf
(2,4-Di-tBuPhO)3PAuCI/AgNTf2
a
Reactions conducted on a 50 mg scale.
Starting alcohol
R1
R2
1a
1d
1e
1f
1p
1r
1s
H
H
H
H
c-C6H11
i-C4H9
t-C4H9
which had given us the highest yield of 5a, as catalyst (Table 3).
Sulfamidate 5b was formed as exclusively the E-alkene (entry 1) in
excellent yield. Sulfamate 3c, leading to the formation of sulfami-
date 5c containing a trisubstituted olefin, was also a viable sub-
strate under these conditions. Sulfamates 3def, derived from
secondary alcohols, gave mixtures of 1,3-cis and trans isomers.
It would not be possible to prepare these sulfamidates regio-
selectively from the Rh-nitrene chemistry of sulfamates, where
insertion into tertiary CeH bonds is faster than that into allylic and
benzylic CeH bonds, and aziridination often predominates over
allylic CeH insertion.16e19 The hydroamination route thus de-
scribed provides access to sulfamidate substitution patterns com-
plementary to those available by other means.
In the case of sulfamidate 5a the diastereomers were separable
and the major product was shown to be the 1,3-cis isomer (cis-5a)
by a single crystal X-ray diffraction study (see Supplementary
data); the other 1,3-disubstituted products were assigned by
analogy.20
The 2-substituted product 5g was formed as a 3:1 mixture of
diastereomers. Initially, we were unable to separate these di-
astereomers by chromatography or determine the relative
CH2CH2Ph
e(CH2)5e
H
H
E-CH]CHePh
E-CH]CHeC3H7
a
For experimental details see Supplementary data.
Our initial test substrate 3a (Table 2) was prepared by route A in
three steps from cyclohexane carbaldehyde. We were pleased to
find that treatment of 3a with commercially available PPh3AuNTf2
(Gagosz’s complex)14 or PPh3AuCl/AgOTf15 at room temperature in
dichloromethane led to the clean formation of the expected sulfa-
midate 5a (entries 4 and 5). Use of other ligands and counterions on
gold (entries 6e8) gave better diastereoselectivity in some cases,
but with diminished yield. Control experiments without any cata-
lyst, with AgOTf only and with TfOH confirmed that the gold
complex was necessary for reaction to occur (entries 1e3).
We then prepared a range of substituted substrates designed to
demonstrate the scope of the reaction using Gagosz’s complex,

M.C.M. Higginbotham et al. / Tetrahedron 71 (2015) 727e737
729
Table 3
X-ray diffraction study were then obtained, revealing this product
to be 2,3-cis-5g. Comparison of the 1H and 13C NMR data with those
obtained from the mixture arising from the gold-catalysed cycli-
sation confirmed that the cis diastereomer was indeed the original
major product.
Mono- and disubstituted sulfamidates
A control experiment, performed by subjecting the separable
diastereomer cis-5a to the original reaction conditions, showed that
no equilibrium existed between the diastereomers. This is consis-
tent with a kinetically controlled cyclisation, which is common in
other gold-catalysed hydroaminations.4e6
Mechanistically, we anticipate that the reaction occurs via an
outer sphere mechanism23e28 (Scheme 4) leading to anti amino-
auration of the allene. The cis and trans diastereomeric products
may arise from the conformations A and A0 indicated.
stereochemistry of the major isomer by NMR experiments. We
therefore planned to convert the diastereomeric mixture into the
corresponding known21 syn- and anti-tosyl-protected amino alco-
hols 6 (Scheme 3) to elucidate the nature of the major product.
Scheme 4. Working stereochemical hypothesis.
Protonation of the vinyl gold intermediates B and B0 would then
give the observed products and regenerate the catalyst. Addition of
protic additives (H2O, AcOH, TfOH) to the reaction mixture did not
accelerate the reaction to a measurable extent, suggesting that the
final protonation is not the rate-determining step of this process.
The diastereoselectivity observed in the formation of 5a, 5d, 5e
and 5f is lower than that normally found in related cyclisations.23
The explanation for this is currently unclear. At present, we pos-
tulate that A and A0 (Scheme 4, part I) are in equilibrium29 and that
the observed diastereoselectivity for the cis-products is due to
faster and irreversible cyclisation of A, which has both the sub-
stituent R and the allene in equatorial positions. This would com-
pare favourably with cyclisation of A0, where the allene is in the
axial position.
O O
OH NHTs
S
O
NH
6
Me
Me
5g (3 : 1 diastereomeric mixture)
(known compounds)
Boc2O, DMAP
O O
O O
S
OH NHBoc
H2O
S
O
NH
O
NBoc
MeCN
heat
Me
Me
7
5g
8 not formed
Me
72% (X-ray structure obtained)
50% (single diastereomer)
The observed diastereoselectivity in the formation of the 2-
substituted system 5g was initially somewhat surprising and does
not seem to have such a straightforward explanation. If the major
product arose simply from a reactive conformation with the max-
imum possible number of equatorial substituents, then the major
diastereomer would be expected to arise from conformation C
(Scheme 4, part II), with both the gold-bound allene and the methyl
group in equatorial positions. This would lead to the preferential
formation of the trans product, but we have demonstrated un-
equivocally that the major product is cis-5g. Assuming a chair-like
Scheme 3. Determination of diastereoselectivity for 5g.
However, we did not ultimately need to carry out this lengthy
sequence in full. Boc-protection of the mixture 5g led unexpectedly
to the isolation of a single diastereomeric product 7 in moderate
yield. We were once again unable to crystallise this compound, but
attempted ring-opening using water in boiling acetonitrile led only
to slow loss of the Boc group (presumably by a thermal mecha-
nism22) to give a single diastereomer of 5g. Crystals suitable for an

730
M.C.M. Higginbotham et al. / Tetrahedron 71 (2015) 727e737
transition state, two reactive conformations leading to the cis-
products are C0 and C00 leading to D0 and D00, respectively. There is no
obvious reason why C0, with the allene in the axial position, would
be favoured over C, and indeed the steric bulk of the nearby sub-
stituent R is likely to clash with the metaleligand assembly. Con-
formation C00 is thus probably more likely to be responsible for the
formation of the major productdthe gold-bound allene is equa-
torial, and although the group R is now axial, it is now less likely to
interfere with the metaleallene binding. This would also be con-
sistent with our analysis of the 1,3-disubstituted systemsdthe
allene is equatorial in the suggested favoured conformation A, but
substituent R is perhaps in this case sufficiently distant not to affect
the metaleallene interaction when in the equatorial position. A
fourth possible conformation of 3g that would give rise to trans-5g,
with both substituents in axial positions, was considered energet-
ically unlikely.
conditions, leading to densely functionalised products 5kem (en-
tries 4e6). The current limitof the method was reached in the case of
substrate 3n, which gave only a trace (w3%) of product 5n after 5
days at 40 ꢀC (entry 7), presumably for steric reasons. These poly-
functional unsaturated amine derivatives are difficult to access by
other methods34,35 and can potentially participate in a number of
chemoselective transformations. General catalytic asymmetric ap-
proaches to C-tertiary amines have so far proved very difficult to
realise. We feel that this new hydroamination reaction can poten-
tially contribute to solving this important problem.34e40
We also prepared a number of substrates 3oer, 9 and 10, which
served to demonstrate the current limitations of this process
(Fig. 1). Sulfamate 3o (bearing adjacent substituents) and 9 (re-
quiring formation of a seven-membered ring) were found to be
unreactive under all conditions attempted, with various Au com-
plexes. Tertiary alcohol-derived sulfamate 3p and compound 3q,
bearing a phenyl-substituted allene, underwent decomposition to
unidentifiable products upon treatment with any of the potential
catalysts, with no evidence of product formation, as judged by 1H
NMR spectra of the crude reaction mixtures. Compounds 3r and 3s
could not be purified chromatographically and did not appear to be
stable under ambient conditions (although evidence for their for-
mation was seen in the crude 1H NMR spectra of the sulfamoylation
reactions).
We continued our studies by preparing substrates that could lead
to the formation of N-substituted quaternary centres30 (Table 4),
since this is very rare for catalytic hydroaminations.31e33 Gratify-
ingly, cyclisation of sulfamates 3hej occurred cleanly to give the
respective products 5hej (entries 1e3). Substrates 3kem, bearing
protected hydroxyl groups, were also compatible with these
Table 4
Formation of N-substituted quaternary centres
Fig. 1. Unsuccessful substrates.
Compound 10, which would in theory lead to a five-membered
sulfamidate, could not be prepared and all attempts at sulfamoy-
lation of the corresponding alcohol led only to complete de-
composition. Robertson and co-workers made similar observations
regarding related compounds9 and it seems likely that these par-
ticular allenic sulfamates are not viable reagents. Our attempts to
prepare alcohol 2t, intended for subsequent sulfamate formation,
were stalled by a lack of reactivity in the desired JohnsoneClaisen
rearrangement step. To the best of our knowledge, there appear to
be no examples in the literature of such rearrangements involving
substrates containing basic amines.
Intriguingly, our attempts to conduct the JohnsoneClaisen
rearrangement of 3-allyl propargyl alcohol 4u resulted in very small
and variable amounts of the expected ester 11 (Scheme 5A). The
major product from this reaction was found to be conjugated diene
12, isolated as a single diastereomer,41 but which obviously could
not easily be converted to the desired alcohol 13. This product
presumably results from acid-catalysed isomerisation42 of the first-
a Ph3PAuNTf2, DCM, r.t. 24-120 h, see ESI. b ~3% of 90% pure product isolated.

M.C.M. Higginbotham et al. / Tetrahedron 71 (2015) 727e737
731
formed allene under the reaction conditions. Further investigations
are continuing into optimising the yield, scope and selectivity of
this process. As an alternative route to our desired ene-allene
substrate 16 (Scheme 5B), we prepared the known tosylate43 14
and conducted an SN20 reaction using an allyl cuprate44 to give
protected ene-allene 15 in modest yield. Removal of the silyl group
and sulfamoylation then gave the desired hydroamination sub-
strate 16.
Scheme 6. Possible cycloisomerisation mechanism.
amidine 21. It is currently unclear whether acylation of the nitrile
occurs before or after the 5-exo-dig cyclisation of the amine onto
the nitrile, leading to 21. Related reactions are normally carried out
in strong acid or base in two separate steps, rather than the rela-
tively mild one-pot conditions found here.47
Scheme 7. An unusual acyl amidine synthesis.
Scheme 5. (A) Unexpected isomerisation to give diene 12 and (B) successful synthesis
and ene-allene cycloisomerisation of 16 to give cyclopropane 17.
3. Conclusion
Treatment of 16 with the gold(I) complex under our standard
conditions did not lead to formation of the hydroamination product
18. Instead, the sole product isolated after only 30 min was found to
possess some alkyl protons with 1H NMR signals at very low
In summary, we have presented our full results on the first gold-
catalysed preparation of cyclic sulfamidates, leading to a range of
unusually substituted and sterically hindered products under mild
conditions. We have proposed a model for the diastereoselectivity
of these reactions for different substitution patterns and demon-
strated the current scope and limitations of this new reaction. We
are currently exploring further improvements to the catalyst sys-
tem, development of an asymmetric version of this process and
broadening our studies to other metal-catalysed reactions of sul-
famates and related compounds. We are also examining the scope
of the unexpected cycloisomerisation and amidine cyclisations.
chemical shift (
d¼0.68 and 0.0 ppm relative to CDCl3 at 7.27 ppm). It
was identified by 1D and 2D NMR studies as fused cyclopropane 17.
Mechanistically, product 17 may result from ene-allene cyclo-
isomerisation as depicted in Scheme 6. Thus, co-ordination of Au(I)
to the allene initiates an intramolecular cyclopropanation to give
carbene G via transition state F. Loss of a proton then gives vinyl
gold intermediate H, after which protodemetallation leads to 17.
This mechanism is related to one, which was elucidated by Fen-
sterbank, Malacria and Nolan from computational and experi-
mental studies on Au(I)- and Pt(II)-catalysed reactions on more
elaborate allenenyl esters.45 The fact that none of the expected
product 18 was detected at all suggests that the rearrangement is
more than one order of magnitude faster than the hydroamination,
with the sulfamate nucleophile acting as merely a spectator.
Finally, during our investigations into the reactivity of these
sulfamidates, we discovered unusual behaviour leading to a novel
acyl amidine synthesis (Scheme 7). Allylation46 of 5h to give 19 and
ring-opening with cyanide ion occurred as expected to give the
cyanoamine 20 after acid hydrolysis of the N-sulfate intermediate.1
Exposure of 20 to standard acylation conditions gave not the ex-
pected acetamide, but a product ultimately identified as the
4. Experimental
4.1. General
1H NMR spectra were recorded on Bruker AV 300, DPX 400 and
AV 400 spectrometers at 300 and 400 MHz, respectively, and ref-
erenced to residual solvent. 13C NMR spectrum was recorded using
the same spectrometers at 75 and 100 MHz, respectively. Chemical
shifts (d in parts per million (ppm)) were referenced to tetrame-
thylsilane (TMS) or to residual solvent peaks (CDCl3 at dH 7.26). J
values are given in hertz (Hz) and s, d, dd, t, q and m abbreviations
correspond to singlet, doublet, doublet of doublet, triplet, quartet

732
M.C.M. Higginbotham et al. / Tetrahedron 71 (2015) 727e737
and multiplet. Mass spectra were obtained at the EPSRC National
Mass Spectrometry Service Centre in Swansea. Infrared spectra
were obtained on PerkineElmer Spectrum 100 FT-IR Universal ATR
Sampling Accessory, deposited neat or as a chloroform solution to
a diamond/ZnSe plate.
Flash column chromatography was carried out using Matrix
silica gel 60 from Fisher Chemicals and TLC was performed using
Merck silica gel 60 F254 precoated sheets and visualised by UV
(254 nm) or stained by the use of aqueous acidic KMnO4. Anhy-
drous dichloromethane (DCM) and anhydrous dichloroethane
(DCE) were distilled from CaH2.
(95%); HRMS (ESIþ) found 437.2683, C28H37O4 (2MþH)þ requires
437.2686.
4.2.4. 3-((Benzyloxy)methyl)penta-3,4-dien-1-ol (2l). Wt 2.4 g;
88%; colourless oil; nmax/cmꢁ1 3371, 3030, 2859, 1956, 1496, 1453,
1355, 1205, 1027, 849, 687, 737; dH (300 MHz, CDCl3) 7.43e7.26 (5H,
m, Ph), 4.86e4.82 (2H, m, CH2]), 4.56 (2H, s, CH2Ph), 4.08 (2H, t, J
1.9 Hz, CH2OCH2Ph), 3.78 (2H, t, J 6.0 Hz, CH2OH), 2.59e2.50 (1H, s,
OH), 2.37 (2H, tt, J 6.0, 1.9 Hz, CH2CH2OH); dC (75 MHz, CDCl3) 207.5,
137.7, 128.5, 128.0, 127.8, 97.7, 75.8, 72.0, 71.4, 61.3, 33.5; m/z (ESIþ)
205 (MþHþ, 100%), 113 (39%), 107 (67%); HRMS (ESIþ) found
205.1223, C13H17O2 (MþH)þ requires 205.1223.
4.2. Experimental section
4.2.5. 3-(Methoxymethyl)penta-3,4-dien-1-ol (2m). Wt 3.30 g; 52%;
colourless oil; nmax/cmꢁ1 3385, 2927, 2822, 1957, 1728, 1450, 1375,
1179, 1084, 848; dH (300 MHz, CDCl3) 4.84e4.75 (2H, m, CH2]),
3.94 (2H, t, J 2.0 Hz, CH2OCH3), 3.74 (2H, t, J 5.9 Hz, CH2OH), 3.34
(3H, s, CH3), 2.55 (1H, br s, OH), 2.30 (2H, tt, J 5.9, 2.0 Hz,
CH2CH2OH); dC (100 MHz, CDCl3) 207.3, 97.5, 75.5, 73.6, 61.1, 57.6,
33.3; m/z (ESIþ) 129 (MþHþ, 68%), 97 (100%); HRMS (ESIþ) found
129.0909, C7H13O2 (MþH)þ requires 129.0910.
Homopropargyl alcohols (1a,48 1d,49 1e,50 1f,48 1p,51 1r,48 1s52
)
were prepared by Barbier-type reactions.48,53 Propargyl alcohols 4c,
4g, 4h, 4o and 4q are commercially available. Propargyl alcohols
(4b,11 4i,54 4j,55 4k,56 4l,57 4m,58 4n,59 4t,60 4u61) were prepared by
known methods.
Allenic alcohols (2a,62 2d,63 2e,64 2f,63 2p,65 2r63 and 2s63) were
ꢀ
prepared by the Crabbe homologation of homopropargyl alco-
hols.66 Allenic alcohols (2b,67 2c,11 2g,10 2h,68 2i,69 2j, 2k, 2l, 2m, 2n,
2o11 and 2q11) were prepared by the JohnsoneClaisen rearrange-
ment of the corresponding propargyl alcohol.11
4.2.6. 3-Isopropylpenta-3,4-dien-1-ol (2n). Wt 1.1 g; 72%; colour-
less oil; nmax/cmꢁ1 3316, 2962, 2931, 2871, 1953, 1465, 1041, 844; dH
(300 MHz, CDCl3) 4.81e4.77 (2H, m, CH2]), 3.75 (2H, dd, J 6.0 Hz,
CH2OH), 2.30e2.16 (2H, m, CH2CH2OH), 2.16e2.03 (1H, m,
CH(CH3)2), 1.78e1.56 (1H, m, OH), 1.04 (6H, d, J 6.8 Hz, CH(CH3)); dC
(75 MHz, CDCl3) 204.3, 106.7, 77.6, 61.1, 33.3, 30.7, 21.5; m/z (ESIþ)
127 (MþHþ, 100%), 110 (30%), 109 (35%); HRMS (ESIþ) found
126.1038, C8H14O (Mþ) requires 126.1039.
4.2.1. 3-(Cyclohexylmethyl)penta-3,4-dien-1-ol (2j). Wt 2.0 g; 66%;
colourless oil; nmax/cmꢁ1 3326, 2920, 2850, 1957, 1448, 1045, 1015,
842; dH (300 MHz, CDCl3) 4.74e4.68 (2H, m, CH2]), 3.74 (2H, dd, J
11.1, 5.6 Hz, CH2OH), 2.25e2.12 (2H, m, CH2CH2OH), 1.90e1.71 (2H,
m, CH2C), 1.70e1.58 (4H, m, C6H11), 1.53e1.32 (1H, m, CH2CH),
1.31e1.09 (4H, m, C6H11), 1.07e0.75 (2H, m, C6H11). Further char-
acterised by preparation of the 4-nitrobenzoate ester due to
instability.
4.3. General procedure for the preparation of allenic
sulfamates18,70
Allenic sulfamates 3a,70 3b,67 3c, 3d, 3e, 3f, 3g, 3h,54 3i, 3j, 3k, 3l,
3m, 3n,55 3o, 3p, 3q and 3s were prepared as outlined below.
Under an inert atmosphere (nitrogen), formic acid (2.5 equiv)
was added dropwise to neat chlorosulfonylisocyanate (2.5 equiv),
at 0 ꢀC with vigorous stirring. Acetonitrile (0.8 mL/mmol alcohol)
was added and the reaction mixture stirred overnight. The allenic
alcohol was dissolved in dimethylacetamide (1.7 mL/mmol alco-
hol) and added dropwise to the sulfamoyl chloride solution at
4.2.2. 3-(Cyclohexylmethyl)penta-3,4-dien-1-yl 4-nitrobenzoate es-
ter. To
a solution of 3-(cyclohexylmethyl)penta-3,4-dien-1-ol
(108 mg, 0.6 mmol) in dichloromethane (1 mL) were added trie-
thylamine (85 mg, 0.8 mmol) and dimethylaminopyridine (6.8 mg,
56 m
mol). To the stirring solution at 0 ꢀC was added p-nitro ben-
zoylchloride (128 mg, 0.7 mmol) in dichloromethane (1 mL)
dropwise and stirred for 30 min. The reaction mixture was stirred
at room temperature for 18 h. Water (10 mL) was added. The sep-
arated organic layer was washed with hydrochloric acid (10%;
2ꢂ1 mL), water (5 mL) then brine (5 mL) and dried (Na2SO4) and
concentrated in vacuo. Purification by column chromatography
(20:1 petroleum ether/ethyl acetate) afforded the title compound.
Wt 140 mg; 76%; colourless oil; nmax/cmꢁ1 2922, 2850, 1957, 1724,
1527, 1347, 1268, 842; dH (300 MHz, CDCl3) 8.33e8.22 (2H, m,
2ꢂCHCNO2), 8.22e8.14 (2H, m, 2ꢂCHCCO), 4.67e4.62 (2H, m,
CH2]), 4.45 (2H, t, J 6.7 Hz, CH2O), 2.39 (2H, tt, J 6.7, 3.2 Hz,
CH2CH2O), 1.89 (2H, dt, J 6.7, 2.7 Hz, CH2CH), 1.80e1.54 (5H, m,
C6H11), 1.53e1.32 (1H, m, C6H11), 1.32e1.06 (2H, m, C6H11),
1.00e0.76 (3H, m, C6H11); dC (75 MHz, CDCl3) 206.3, 164.6, 150.5,
135.8, 130.7, 123.5, 97.4, 75.7, 64.1, 40.5, 35.9, 33.3, 31.0, 26.5, 26.2;
m/z (ESIþ) 347 (M þ NHþ4 , 100%); HRMS (ESIþ) found 347.1963,
0
ꢀC. Transfer of the alcohol was made quantitative with an ad-
ditional 0.5 mL of dimethylacetamide. The resulting white sus-
pension was stirred for at
ꢀC. Once TLC indicated
2
h
0
consumption of starting material, the reaction mixture was diluted
with ethyl acetate and brine and poured into a separating funnel
containing ethyl acetate and water. The separated aqueous phase
was further extracted with ethyl acetate and the combined organic
layer washed with brine, dried (Na2SO4) and concentrated in
vacuo. Purification by column chromatography provided the de-
sired sulfamate ester.
4.3.1. 4-Cyclohexylidene-3-en-1-yl sulfamate (3c). Wt 429 mg; 58%;
colourless oil; nmax/cmꢁ1 3385, 3282, 2925, 2853, 1966, 1554, 1446,
1359, 1266, 1239, 1175, 978, 924, 851, 825, 797, 739; dH (300 MHz,
CDCl3) 5.10e4.85 (1H, m, CH]), 4.68 (2H, s, NH2), 4.25 (2H, t, J
6.9 Hz, CH2O), 2.41 (2H, dt, J 13.3, 6.9 Hz, CH2CH2O), 2.17e2.05 (4H,
m, C6H10),1.69e1.35 (6H, m, C6H10); dC (75 MHz, CDCl3) 199.3,104.0,
83.2, 70.8, 31.5, 28.9, 27.3, 26.0; m/z (ESIþ) 249 (M þ NH4þ, 100%),
232 (MþHþ, 40%); HRMS (ESIþ) found 232.1004, C10H18O3NS
(MþH)þ requires 232.1002.
C
19H27O4N2 (MþNH4)þ requires 347.1965.
4.2.3. 3-(2-(Benzyloxy)ethyl)penta-3,4-dien-1-ol (2k). Wt 2.4 g;
42%; colourless oil; nmax/cmꢁ1 3406, 2927, 2881, 1715, 1453,1273,
713; dH (300 MHz, CDCl3) 7.39e7.25 (5H, m, Ph), 4.77e4.73 (2H, m,
CH2]), 4.52 (2H, s, CH2OPh), 3.75 (2H, dd, J 6.0 Hz, CH2OH), 3.60
(2H, t,
J 6.6 Hz, CH2OCH2Ph), 2.30 (2H, td, J 6.6, 3.2 Hz,
CH2CH2OCH2Ph), 2.24 (2H, td, J 6.0, 3.2 Hz, CH2CH2OH); dC (75 MHz,
CDCl3) 206.0, 134.6, 129.1, 128.5, 127.9, 97.5, 77.4, 73.2, 68.7, 60.8,
35.7, 32.3; m/z (ESIþ) 219 (MþHþ, 30%), 213 (100%), 197 (50%), 195
4.3.2. 2-Methylocta-6,7-dien-4-yl sulfamate (3d). Wt 421 mg; 71%;
yellow oil; nmax/cmꢁ1 3362, 3283, 2951, 2935,1957,1539,1351,1329,
1178; dH (300 MHz, CDCl3) 5.15e5.10 (1H, m, CH]), 4.86e4.39 (3H,

M.C.M. Higginbotham et al. / Tetrahedron 71 (2015) 727e737
733
m, CH2] and CHO), 2.58e2.42 (3H, m, 1ꢂCH2CH] and
CHCH2CHO), 1.88e1.66 (3H, m, 1ꢂCH2CH and NH2), 1.61e1.38 (1H,
m, CH(CH3)2), 0.96 (3H, d, J 6.2 Hz, CH(CH3)(CH3)), 0.94 (3H, d, J
6.2 Hz, CH(CH3)(CH3)); dC (75 MHz, CDCl3) 209.7, 84.6, 82.7, 75.3,
42.8, 33.8, 24.3, 22.9, 22.2; m/z (ESIþ) 218 (MꢁHþ, 100%); HRMS
(ESIþ) found 218.0852, C9H16O3NS (MꢁH)þ requires 218.0856.
(M þ NHþ4 , 100%), 298 (MþHþ, 35%); HRMS (ESIþ) found 298.1115,
C
14H20O4NS (MþH)þ requires 298.1108.
4.3.9. 3-((Benzyloxy)methyl)penta-3,4-dien-1-yl sulfamate (3l). Wt
1.1 g; 88%; colourless solid; mp 45e46 ꢀC; nmax/cmꢁ1 3277, 1959,
1559, 1454, 1363, 1185, 1065, 978, 924, 857, 747, 699; dH (300 MHz,
CDCl3) 7.36e7.18 (5H, m, Ph), 4.82e4.77 (2H, m, CH2]), 4.75 (2H, s,
NH2), 4.52 (2H, s, CH2Ph), 4.37 (2H, t, J 6.8 Hz, CH2OSO2NH2), 4.10
(2H, t, J 2.6 Hz, PhCH2OCH2), 2.53 (2H, tt, J 6.8 2.6 Hz, CH2CH2O-
SO2NH2); dC (75 MHz, CDCl3) 207.0, 137.8, 128.5, 128.0, 127.9, 95.9,
77.0, 71.9, 71.1, 69.4, 28.8; m/z (ESIþ) 306 (MþNaþ, 100%), 328 (30%),
301 (97%); HRMS (ESIþ) found 306.0775, C13H17NaNO4S (MþNa)þ
requires 306.0770.
4.3.3. 2,2-Dimethylhepta-5,6-dien-3-yl sulfamate (3e). Wt 257 mg;
41%; yellow oil; nmax/cmꢁ1 3381, 2964, 2881, 1957, 1365, 1176,
907; dH (300 MHz, CDCl3) 5.28 (1H, ddt, J 8.2, 6.6 Hz), 4.86e4.62
(4H, m, CH2] and NH2), 4.47e4.43 (1H, m, CHO), 2.62e2.31 (2H,
m, CH2CHO), 1.03 (9H, s, C(CH3)3); dC (75 MHz, CDCl3) 209.2,
92.6, 87.4, 75.6, 35.4, 30.4, 26.1; m/z (ESIþ) 220 (MþHþ, 100%),
HRMS (ESIþ) found 220.0853, C9H17O3NS (MþH)þ requires
220.0856.
4.3.10. 3-(Methoxymethyl)penta-3,4-dien-1-yl sulfamate (3m). Wt
0.5 g; 48%; colourless oil; nmax/cmꢁ1 3273, 2929, 1958, 1563, 1452,
1361, 1180, 1079, 975, 924, 856, 774; dH (300 MHz, CDCl3) 4.94 (2H,
br s, NH2), 4.89e4.81 (2H, m, CH2]), 4.33 (2H, t, J 6.8 Hz, ]CCH2O),
3.95 (2H, t, J 2.1 Hz, CH2OSO2NH2), 3.32 (3H, s, OCH3), 2.54e2.40
(2H, m, CH2CH2OSO2NH2); dC (75 MHz, CDCl3) 206.8, 95.7, 76.9,
73.4, 69.3, 57.7, 28.6; m/z (ESIþ) 230 (MþNaþ, 100%), 208 (40%), 176
(32%), 149 (9%); HRMS (ESIþ) found 230.0459, C7H13O4NSNa
(MþNa)þ requires 230.0457.
4.3.4. 1-Phenylhepta-5,6-dien-3-yl sulfamate (3f). Wt 614 mg; 86%;
colourless oil; nmax/cmꢁ1 3379, 3281, 2928, 1956, 1355, 1177, 912; dH
(300 MHz, CDCl3) 7.36e7.14 (5H, m, Ph), 5.19e5.03 (1H, m, CH]),
4.70 (5H, m, CH2], NH2 and CHO), 2.88e2.66 (2H, m, CH2Ph),
2.55e2.49 (2H, m, CH2CH]), 2.15e2.02 (2H, m, CH2CH2CHO); dC
(75 MHz, CDCl3) 209.7, 141.0, 128.6, 128.4, 126.2, 84.4, 83.3, 75.4,
35.2, 33.4, 31.2; m/z (ESIþ) 268 (MþHþ, 100%), 204 (45%), 163 (30%);
HRMS (ESIþ) found 268.1272, C13H18O3NS (MþH)þ requires
268.1267.
4.3.11. 2-Methyl-3-vinylideneheptyl sulfamate (3o). Wt 925 mg;
78%; colourless oil; nmax/cmꢁ1 3286, 2958, 2931, 2874, 1954, 1363,
1181, 908; dH (300 MHz, CDCl3) 4.84e4.60 (2H, m, CH2]), 4.23 (1H,
dd, J 9.4, 5.7 Hz, 1ꢂCH2OSO2NH2), 3.98 (1H, dd, J 9.4, 8.0 Hz,
1ꢂCH2OSO2NH2), 2.50e2.27 (1H, m, CHCH3), 2.11e1.90 (2H, m,
NH2), 1.50e1.15 (6H, m, CH2CH2CH2CH3), 1.13 (3H, d, J 6.8 Hz,
CHCH3), 0.90 (3H, t, J 7.1 Hz, CH2CH3); dC (75 MHz, CDCl3) 205.1,
104.3, 78.0, 74.5, 35.3, 30.5, 29.7, 22.4, 16.5, 13.9; m/z (ESIþ) 273
(M þ NHþ4 , 100%), 241 (15%), 154 (15%), 137 (70%); HRMS (ESIþ)
found 251.1423, C10H23O3N2S (MþNH4)þ requires 251.1424.
4.3.5. 2-Methylpenta-3,4-dien-1-yl sulfamate (3g). Wt 60 mg; 67%;
colourless oil; nmax/cmꢁ1 3376, 3283, 2974, 1956, 1357, 1175, 972,
919; dH (300 MHz, CDCl3) 5.14 (1H, dd, J 13.1, 6.4 Hz, CHCH]),
4.85e4.77 (2H, m, CH2]), 4.76 (2H, s, NH2), 4.14 (1H, dd, J 9.4,
6.4 Hz, 1ꢂCH2OSO2NH2), 4.04 (1H, dd,
J
9.4, 7.0 Hz,
1ꢂCH2OSO2NH2), 2.72e2.52 (1H, m, CHCH3), 1.12 (3H, d, J 6.9 Hz,
CH3); dC (75 MHz, CDCl3) 208.0, 91.2, 77.2, 75.0, 32.2, 16.5; m/z
(ESIþ) 250 (MþOAcþ, 100%), 236 (15%); HRMS (ESIþ) found
178.0529, C6H11O3NS (MþH)þ requires 178.0532.
4.3.12. 1-(Buta-2,3-dien-1-yl)cyclohexyl sulfamate (3p). Wt 191 mg;
74%; white solid; mp 71 ꢀC; nmax/cmꢁ1 3277, 2927, 2854, 1645, 1408,
1361, 1175, 870; dH (300 MHz, CDCl3) 5.48 (1H, ddd, J 8.6, 3.5, 1.4 Hz,
]CH), 5.16e4.99 (2H, m, ]CH2), 2.64 (2H, d, J 8.6 Hz, CH2CH]),
1.98e1.47 (12H, m, C6H10 and NH2); dC (75 MHz, CDCl3) 208.9,136.3,
121.9, 88.4, 74.3, 37.4, 28.2, 25.2, 22.9, 22.5; m/z (ESIþ) 249
(M þ NHþ4 , 100%), 244 (70%); HRMS (ESIþ) found 249.0774,
4.3.6. 3-Vinylidenenonyl sulfamate (3i). Wt 1.3 g; 43%; colourless
oil; nmax/cmꢁ1 3283, 2957, 2927, 2858, 1958, 1724, 1361, 1125; dH
(300 MHz, CDCl3) 4.86e4.64 (4H, m, CH2] and NH2), 4.30 (2H, t, J
7.1 Hz, CH2O), 2.38 (2H, tt, J 6.9, 3.3 Hz, CH2CH2CH2C]), 2.03e1.89
(2H, m, CH2CH2O), 1.70e1.19 (8H, m, (CH2)4CH3), 0.89 (3H, dd, J 9.4,
4.2 Hz, CH3); dC (75 MHz, CDCl3) 205.5, 98.7, 77.2, 69.5, 32.3, 31.7,
31.0, 28.9, 27.3, 22.6, 14.1; m/z (ESIþ) 265 (M þ NH4þ, 100%), 255
(15%); HRMS (ESIþ) found 265.1584, C11H25O3N2S (MþNH4)þ re-
quires 265.1580.
C
10H21O3N2S (Mþ) requires 249.0779.
4.3.13. 2-Methyl-3-phenylpenta-3,4-dien-1-yl sulfamate (3q). Wt
655 mg; 65%; white solid; mp 79e81 ꢀC; nmax/cmꢁ1 3416, 3310,
2982, 2970, 1933, 1542, 1464, 1330, 1170; dH (300 MHz, CDCl3)
7.44e7.16 (5H, m, Ph), 5.27e5.11 (2H, m, CH2]), 4.62 (2H, s, NH2),
4.34 (1H, dd, J 9.6, 5.3 Hz, 1ꢂCH2OSO2NH2), 4.06 (1H, dd, J 9.6,
8.1 Hz, 1ꢂCH2OSO2NH2), 3.23e3.01 (1H, m, CHCH3), 1.27 (3H, d, J
6.8 Hz, CH3); dC (75 MHz, CDCl3) 207.9, 135.1, 128.7, 127.2, 126.3,
106.7, 80.4, 74.5, 32.6, 17.0; m/z (ESIþ) 271 (M þ NH4þ, 100%), 157
(60%); HRMS (ESIþ) found 271.1115, C12H19O3N2S (MþNH4)þ re-
quires 271.1111.
4.3.7. 3-(Cyclohexylmethyl)penta-3,4-dien-1-yl sulfamate (3j). Wt
1.1 g; 76%; colourless oil; nmax/cmꢁ1 3274, 2921, 2851, 1959, 1709,
1561, 1448, 1363, 1176; dH (300 MHz, CDCl3) 4.79e4.50 (4H, m,
CH2] and NH2), 4.29 (2H, t, J 7.0 Hz, CH2O), 2.36 (2H, tt, J 7.0, 3.4 Hz,
CH2CH2O), 1.91e1.82 (2H, m, CH2C6H11), 1.82e1.57 (4H, m,
4ꢂC6H11), 1.51e1.32 (1H, m, CH2CH), 1.31e0.99 (4H, m, 4ꢂC6H11),
0.99e0.73 (2H, m, 2ꢂC6H11); dC (75 MHz, CDCl3) 206.0, 96.9, 76.4,
69.5, 40.5, 35.8, 33.3, 31.0, 26.5, 26.2. This compound decomposed
rapidly; good MS/HRMS data could not be obtained. It had to be
subjected to the hydroamination conditions immediately for re-
producible yields of 5j.
4.4. Cyclic sulfamidates (5ae5n)10
4.3.8. 3-(2-(Benzyloxy)ethyl)penta-3,4-dien-1-yl sulfamate (3k). Wt
609 mg; 76%; colourless oil; nmax/cmꢁ1 3280, 2866,1958,1716,1363,
1176; dH (300 MHz, CDCl3) 7.44e7.20 (5H, m, Ph), 4.93e4.63 (4H, m,
CH2] and NH2), 4.53 (2H, s, CH2Ph), 4.33 (2H, t, J 6.7 Hz, CH2O-
SO2NH2), 3.63 (2H, t, J 6.4 Hz, CH2CH2OCH2Ph), 2.44 (2H, tt, J 6.7,
General procedure for gold-catalysed hydroamination
Under an inert atmosphere (nitrogen), the sulfamate was dis-
solved in dry dichloromethane (0.3 M). PPh3AuNTf2 (5 mol %) was
added and the reaction mixture stirred at room temperature. When
starting material was consumed, as determined by TLC, the reaction
mixture was filtered through a plug of silica with diethyl ether, and
concentrated in vacuo. Purification by column chromatography
afforded the title compounds 5aen.
3.2 Hz, CH2CH2OSO2NH2), 2.33 (2H, tt,
J
6.4, 3.2 Hz,
CH2CH2OCH2Ph); dC (100 MHz, CDCl3) 205.6, 161.0, 129.6, 128.4,
127.7, 127.6, 77.2, 73.0, 68.5, 62.1, 32.4, 31.1; m/z (ESIþ) 315

734
M.C.M. Higginbotham et al. / Tetrahedron 71 (2015) 727e737
4.4.1. 6-Cyclohexyl-4-vinyl-1,2,3-oxathiazinane 2,2-dioxide (5a). Wt
60 mg; 99%; cis/trans 1.2:1. cis-5a: white solid; Rf 0.31 (2:1
dichloromethane/hexane); mp 90e91 ꢀC; nmax/cmꢁ1 3276, 2927,
2852, 1650, 1436, 1347, 1175; dH (400 MHz, CDCl3) 5.81 (1H, ddd, J
17.3, 10.6, 5.1 Hz, CH]CH2), 5.38e5.18 (2H, m, CH]CH2), 4.56 (1H,
ddd, J 11.9, 6.4, 2.0 Hz, CHC6H11), 4.31e4.17 (1H, m, CHCH]CH2),
3.98 (1H, d, J 10.3 Hz, NH),1.98e1.43 (8H, m, 6ꢂC6H11 and CH2CHO),
1.36e0.96 (5H, m, 5ꢂC6H11); dC (101 MHz, CDCl3) 135.3, 117.3, 88.3,
56.4, 42.2, 32.5, 28.3, 28.0, 26.3, 25.9, 25.7; m/z (ESIþ) 263
(M þ NHþ4 , 100%), 246 (15%); HRMS (ESIþ) found 263.1428,
3252, 2962, 2877, 1650, 1413, 1346, 1183; dH (300 MHz, CDCl3) cis-
isomer: 5.82 (1H, ddd, J 17.3, 10.6, 5.0 Hz, CH]CH2), 5.42e5.15
(2H, m, CH]CH2), 4.58e4.39 (1H, m, CHO), 4.28e4.15 (2H, m,
CHNH), 1.95e1.82 (1H, m, 1ꢂCH2CHNH), 1.65e1.46 (1H, m,
1ꢂCH2CHNH), 0.98 (9H, s, (CH3)3C); trans-isomer: 6.20 (1H, ddd, J
17.4, 10.7, 5.4 Hz, CH]CH2), 5.42e5.15 (2H, m, CH]CH2), 4.58e4.39
(1H, m, CHO), 4.30e4.01 (2H, m, CHNH), 2.10e1.97 (1H, m,
1ꢂCH2CHNH), 1.95e1.82 (1H, m, 1ꢂCH2CHNH), 0.98 (9H, s,
(CH3)3C); dC (75 MHz, CDCl3) cis-isomer 135.2,117.3, 91.3, 56.3, 34.5,
29.9, 25.4; trans-isomer 135.9, 117.1, 88.5, 55.2, 34.4, 27.8, 25.2; m/z
(ESIþ) 237 (M þ NHþ4 , 100%) HRMS (ESIþ) found 237.1269,
C9H21O3N2S (MþNH4)þ requires 237.1267.
C
11H23O3N2S (MþNH4)þ requires 263.1424. The X-ray diffraction
data have been submitted to the Cambridge Structural Database
(Ref. number CCDC 871548) and the structure was included in our
previous communication.10
4.4.6. 6-Phenethyl-4-vinyl-1,2,3-oxathiazinane 2,2-dioxide (5f). Wt
48 mg; 95%; colourless oil; cis/trans 1.8:1: nmax/cmꢁ1 3263, 3028,
2931, 1603, 1497, 1416, 1360, 1183; dH (400 MHz, CDCl3) cis-isomer:
7.42e7.19 (5H, m, Ph), 5.85 (1H, ddd, J 17.3, 10.6, 5.0 Hz, CH]CH2),
5.41e5.25 (2H, m, CH]CH2), 4.86e4.76 (1H, m, CHO), 4.37e4.24
(1H, m, CHNH), 4.04 (1H, d, J 10.4 Hz, NH), 3.00e2.71 (2H, m,
CH2Ph), 2.22e2.04 (1H, m, 1ꢂCH2CHNH), 2.03e1.86 (2H, m,
CH2CH2Ph), 1.63 (1H, dt, J 14.3, 11.9 Hz, 1ꢂCH2CHNH); trans-
isomer: 7.42e7.19 (5H, m, Ph), 6.16 (1H, ddd, J 17.2, 10.7, 5.5 Hz,
CH]CH2), 5.41e5.25 (2H, m, CH]CH2), 4.91 (1H, m, CHO), 4.54
(1H, d, J 6.8 Hz, NH), 4.37e4.24 (1H, m, CHNH), 3.00e2.71 (2H, m,
CH2Ph), 2.36 (1H, dtd, J 14.4, 9.2, 5.3 Hz, 1ꢂCH2CHNH), 2.03e1.86
(3H, m, CH2CH2Ph and 1ꢂCH2CHNH); dC (75 MHz, CDCl3) cis-
isomer: 140.4, 135.0, 128.8, 128.6, 126.5, 117.5, 83.1, 56.3, 37.1,
35.2, 30.7; trans-isomer: 140.5, 135.6, 128.7, 128.6, 126.4, 117.5,
81.9, 55.0, 36.5, 33.1, 31.1; m/z (ESIþ) 285 (M þ NH4þ, 100%), 214
(60%); HRMS (ESIþ) found 285.1272, C13H21O3N2S (MþNH4)þ re-
quires 285.1267.
trans-5a: colourless oil; Rf 0.15 (2:1 dichloromethane/hexane);
nmax/cmꢁ1 3277, 2927, 2854, 1645, 1408, 1361, 1175, 870; dH
(400 MHz, CDCl3) 6.18 (1H, ddd, J 17.4, 10.7, 5.5 Hz, CH]CH2), 5.28
(1H, ddd, J 10.7, 1.8, 0.7 Hz, 1ꢂCH]CH2), 5.25 (1H, ddd, J 17.4, 1.8,
0.7 Hz, 1ꢂCH]CH2), 4.67e4.56 (1H, m, CHC6H11), 4.48 (1H, d, J
6.6 Hz, NH), 4.29e4.13 (1H, m, CHCH]CH2), 2.08e1.91 (1H, m,
1ꢂCH2CHO), 1.99e1.92 (1H, m, 1ꢂCH2CHO), 1.88 (1H, ddd, J 14.5,
3.9, 2.9 Hz, CHCHO), 1.83e1.61 (5H, m, 5ꢂC6H11), 1.34e0.96 (5H, m,
5ꢂC6H11); dC (101 MHz, CDCl3) 136.0, 117.2, 86.3, 55.3, 41.7, 30.4,
28.4, 28.2, 26.3, 25.8, 25.6; m/z (ESIþ) 263 (M þ NH4þ, 100%), 246
(15%), 149 (15%); HRMS (ESIþ) found 263.1428, C11H23O3N2S
(MþNH4)þ requires 263.1424.
4.4.2. (E)-4-(Hept-1-en-1-yl)-1,2,3-oxathiazinane 2,2-dioxide
(5b). Wt 42 mg; 94%; colourless oil; nmax/cmꢁ1 3245, 2926, 1433,
1346, 1190, 1170; dH (300 MHz, CDCl3) 5.81e5.68 (1H, m, ]CH),
5.44e5.33 (1H, m, ]CH), 4.73 (1H, td, J 11.9, 3.1 Hz, CHNH),
4.58e4.48 (1H, m, 1ꢂCH2O), 4.32e4.16 (2H, m, 1ꢂCH2O and NH),
2.09e1.96 (2H, m, CH2(CH2)3CH3), 1.95e1.72 (2H, m, CH2CHNH),
1.42e1.16 (6H, m, (CH2)3CH3), 0.87 (3H, t, J 6.8 Hz, CH3); dC
(75.5 MHz, CDCl3) 134.9, 126.8, 71.8, 56.9, 32.3, 31.4, 29.9, 28.7, 22.6,
14.1; m/z (ESIþ) 251 (M þ NH4þ, 100%), 216 (6%), 156 (6%); HRMS
(ESIþ) found 251.1428, C10H23O3N2S (MþNH4)þ requires 251.1424.
4.4.7. 5-Methyl-4-vinyl-1,2,3-oxathiazinane 2,2-dioxide (5g). Wt
36 mg; 75%; colourless oil; major/minor 3:1: mp 113 ꢀC; nmax/cmꢁ1
3266, 2977, 1647, 1423, 1358, 1185, 919; dH (400 MHz, CDCl3) major-
isomer: 5.81e5.66 (1H, m, CH]CH2), 5.42e5.23 (2H, m, CH]CH2),
4.84 (1H, dd, J 11.1, 2.5 Hz, 1ꢂCH2O), 4.58e4.42 (2H, m, NH and
CHNH), 4.33 (1H, dd, J 11.5, 1.9 Hz, 1ꢂCH2O), 2.00e1.79 (1H, m,
CHCH3), 1.08 (3H, d, J 7.2 Hz, CH3); minor-isomer: 5.81e5.66 (1H,
m, CH]CH2), 5.42e5.23 (2H, m, CH]CH2), 4.42e4.35 (2H, m,
CH2O), 3.87 (1H, dd, J 17.6, 9.8 Hz, CHNH), 2.00e1.79 (1H, m,
CHCH3), 0.89 (3H, d, J 6.8 Hz, CH3); dC (101 MHz, CDCl3) major-
isomer: 133.9, 117.0, 77.7, 59.8, 30.8, 9.7; minor-isomer: 133.7,
120.1, 76.4, 63.4, 33.3, 12.0; m/z (ESIþ) 195 (M þ NH4þ, 100%), 187
(10%); HRMS (ESIþ) found 195.0794, C6H15O3N2S (MþNH4)þ re-
quires 195.0798.
4.4.3. 4-(Cyclohexylidenemethyl)-1,2,3-oxathiazinane 2,2-dioxide
(5c). Wt 33 mg; 66%; colourless oil; nmax/cmꢁ1 3246, 2922, 1421,
1347, 1187; dH (400 MHz, CDCl3) 5.56e5.42 (1H, m, CH]CH2),
4.78e4.66 (1H, m,1ꢂCH2O), 4.59e4.49 (1H, m,1ꢂCH2O), 4.05e3.71
(2H, m, CHNH), 2.19e2.15 (2H, m, CH2CH2O), 2.06e1.50 (10H, m,
C6H10); dC (101 MHz, CDCl3) 132.1, 126.5, 72.2, 53.8, 44.2, 30.2, 28.5,
25.4, 22.8, 22.2; m/z (ESIþ) 440 (M þ NHþ4 , 100%), 232 (43%), 199
(20%), 149 (27%); HRMS (ESIþ) found 249.1271, C10H21O3N2S
(MþNH4)þ requires 249.1267.
4.4.8. 4-Propyl-4-vinyl-1,2,3-oxathiazinane 2,2-dioxide (5h). Wt
50 mg; 92%; colourless oil; nmax/cmꢁ1 3263, 2963, 2876, 1641, 1407,
1354; dH (400 MHz, CDCl3) 5.97e5.85 (1H, m, CH]CH2), 5.30 (1H, d,
J 11.1 Hz,1ꢂCH]CH2), 5.12 (1H, d, J 17.7 Hz,1ꢂCH]CH2), 4.73e4.64
(1H, m, 1ꢂCH2O), 4.60 (1H, ddd, J 11.8, 5.6, 4.0 Hz, 1ꢂCH2O), 4.28
(1H, s, NH), 2.04e1.96 (1H, m, 1ꢂCH2CH2O), 1.91e1.81 (1H, m,
1ꢂCH2CH2O), 1.81e1.20 (4H, m, (CH2)2CH3), 0.91 (3H, t, J 7.2 Hz,
CH3); dC (101 MHz, CDCl3) 139.9, 115.1, 69.2, 63.0, 43.2, 32.2, 16.2,
14.2; m/z (ESIþ) 223 (M þ NH4þ, 100%), 185 (5%); HRMS (ESIþ) found
223.1113, C8H19O3N2S (MþNH4)þ requires 223.1111.
4.4.4. 6-Isobutyl-4-vinyl-1,2,3-oxathiazinane 2,2-dioxide (5d). Wt
49 mg; 94%; colourless oil; cis/trans 1.8:1: nmax/cmꢁ1 3245, 2960,
2874, 1650, 1413, 1356, 1185; dH (300 MHz, CDCl3) cis-isomer: 5.81
(1H, ddd, J 17.3,10.6, 5.0 Hz, CH]CH2), 5.37e5.22 (2H, m, CH]CH2),
4.90e4.79 (2H, m, CHO and CHNH), 3.90 (1H, d, J 10.2 Hz, NH),
1.96e1.80 (2H, m, CH2CHNH), 1.80e1.66 (1H, m, CH(CH3)2),
1.60e1.45 (2H, m, CH2CH(CH3)2), 1.00e0.87 (6H, m, CH(CH3)2)
trans-isomer: 6.18 (1H, ddd, J 17.3, 10.7, 5.5 Hz, CH]CH2), 5.37e5.22
(2H, m, CH]CH2), 5.00e4.91 (2H, m, CHO and CHNH), 4.44 (1H, d, J
7.1 Hz, NH), 1.96e1.80 (2H, m, CH2CHNH), 1.80e1.66 (1H, m,
CH(CH3)2), 1.44e1.32 (2H, m, CH2CH(CH3)2), 1.00e0.87 (6H, m,
CH(CH3)2); dC (75 MHz, CDCl3) cis-isomer: 135.1, 117.4, 82.7, 56.3,
44.3, 35.6, 23.8, 23.0, 22.0; trans-isomer: 135.9, 117.4, 81.1, 55.2,
43.6, 33.5, 24.1, 23.0, 21.9; m/z (ESIþ) 237 (M þ NH4þ, 100%), HRMS
(ESIþ) found 237.1270, C9H21O3N2S (MþNH4)þ requires 237.1267.
4.4.9. 4-Hexyl-4-vinyl-1,2,3-oxathiazinane 2,2-dioxide (5i). Wt
35 mg; 70%; yellow oil; nmax/cmꢁ1 3264, 2956, 2931, 2859, 1642,
1407, 1356, 1186, 777; dH (300 MHz, CDCl3) 5.91 (1H, dd, J 17.5,
10.8 Hz, CH]CH2), 5.30 (1H, d, J 11.1 Hz, 1ꢂCH]CH2), 5.12 (1H, d, J
17.7 Hz, 1ꢂCH]CH2), 4.77e4.48 (2H, m, CH2O), 4.16 (1H, s, NH),
2.01 (1H, m, 1ꢂCH2CH2O), 1.92e1.70 (2H, m, CH2C), 1.60e1.51 (1H,
m, CH2CH2O), 1.44e1.14 (8H, m, (CH2)4CH3), 0.88 (3H, dd, J 9.3,
4.2 Hz, CH3); dC (75 MHz, CDCl3) 140.0, 115.2, 69.2, 63.0, 41.1, 32.3,
4.4.5. 6-(tert-Butyl)-4-vinyl-1,2,3-oxathiazinane 2,2-dioxide
(5e). Wt 53 mg; 93%; colourless oil; cis/trans 2:1: nmax/cmꢁ1

M.C.M. Higginbotham et al. / Tetrahedron 71 (2015) 727e737
735
31.7, 29.4, 22.8, 22.7, 14.2; m/z (ESIþ) 270 (MþNaþ, 100%); HRMS
(ESIþ) found 270.1138, C11H21O3NNaS (MþNa)þ requires 270.1134.
1ꢂCH2O), 4.30e4.16 (1H, m, CHN), 2.95e2.73 (1H, m, CHCH3), 1.53
(9H, s, C(CH3)3), 0.98 (3H, d, J 7.0 Hz, CHCH3); dC (75 MHz, CDCl3);
150.4, 130.0, 121.5, 85.2, 74.5, 64.7, 31.5, 28.0, 13.4; m/z (ESIþ) 295
(M þ NHþ4 , 100%), 222 (30%); HRMS (ESIþ) found 295.1326,
4.4.10. 4-(Cyclohexylmethyl)-4-vinyl-1,2,3-oxathiazinane 2,2-dioxide
(5j). Wt 37 mg; 37%; colourless oil; nmax/cmꢁ1 3381, 2921, 2850,
1557, 1449, 1348, 1176, 926; dH (300 MHz, CDCl3) 6.00 (1H, dd, J 17.8,
11.1 Hz, CH]CH2), 5.31 (1H, d, J 11.1 Hz, 1ꢂCH]CH2), 5.15 (1H, d, J
17.8 Hz, 1ꢂCH]CH2), 4.77e4.64 (1H, ddd, J 11.8, 9.4, 3.2 Hz,
1ꢂCH2O), 4.56 (1H, ddd, J 11.8, 5.0, 4.1 Hz,1ꢂCH2O), 4.12 (1H, s, NH),
2.06e1.83 (2H, m, CH2CH2O), 1.72e1.37 (6H, m, 6ꢂCH2C6H11),
1.31e1.04 (4H, m, 4ꢂCH2C6H11), 1.04e0.82 (3H, m, 3ꢂCH2C6H11); dC
(101 MHz, CDCl3) 140.2, 115.0, 69.1, 63.4, 49.4, 35.3, 35.0, 33.3, 33.0,
26.4, 26.4, 26.1; m/z (ESIþ) 282 (MþNaþ, 100%), 278 (40%), 163
(30%); HRMS (ESIþ) found 260.1319, C12H22O3NS (MþH)þ requires
260.1315.
C
11H23O5N2S (MþNH4)þ requires 295.1322.
4.4.15. (4S,5R)-5-Methyl-4-vinyl-1,2,3-oxathiazinane 2,2-dioxide
(5g, single diastereomer). tert-Butyl 5-methyl-4-vinyl-1,2,3-
oxathiazinane-3-carboxylate 2,2-dioxide (100 mg, 0.4 mmol) was
dissolved in acetonitrile (4 mL) and water (3 mL) and was stirred at
75 ꢀC for 24 h. After cooling to room temperature aqueous hydro-
chloric acid (1 M; 2 mL) and ethyl acetate (2 mL) were added and
the reaction mixture stirred for 1 h, then basified with aqueous
sodium hydroxide (1 M). The biphasic mixture was extracted with
ethyl acetate (three times). The combined organic layer washed
with brine, dried (MgSO4) and concentrated in vacuo affording the
title compound as a yellow oil. Crystallisation from diethyl ether
4.4.11. (4-(2-Benzyloxy)ethyl)-4-vinyl-1,2,3-oxathiazinane 2,2-
dioxide (5k). Wt 45 mg; 90%; colourless oil; nmax/cmꢁ1 3247,
2874, 1703, 1496, 1455, 1407, 1358, 1187, 778; dH (300 MHz, CDCl3)
7.47e7.26 (5H, m, Ph), 6.00 (1H, ddd, J 17.7, 11.0, 0.6 Hz, CH]CH2),
5.78 (1H, s, NH), 5.34e5.12 (2H, m, CH]CH2), 4.72 (1H, td, J 11.4,
2.4 Hz, 1ꢂCH2O), 4.60e4.41 (3H, m, 1ꢂCH2O and PhCH2O),
3.73e3.53 (2H, m, CH2OCH2Ph), 2.15e1.94 (2H, m, CH2CN),
1.89e1.74 (2H, m, CH2C); dC (75 MHz, CDCl3) 140.3, 137.1, 128.7,
128.1, 128.0, 115.4, 73.5, 68.8, 65.6, 62.4, 40.1, 30.6; m/z (ESIþ) 315
(M þ NHþ4 , 90%), 298 ((MþH)þ, 100%), 149 (25%); HRMS (ESIþ)
found 298.1115, C14H20O4NS (MþH)þ requires 298.1108.
afforded the title compound as
a colourless solid (46 mg,
0.26 mmol, 72%): mp 112e113 ꢀC; dH (300 MHz, CDCl3) 5.76 (1H,
ddd, J 17.2, 10.8, 4.3 Hz, CH]CH2), 5.30 (1H, dd, J 17.2, 1.9 Hz,
1ꢂCH]CH2), 4.86 (1H, dd, J 10.8, 2.5 Hz, 1ꢂCH]CH2), 4.64e4.45
(1H, m, 1ꢂCH2O), 4.33 (1H, dd, J 11.5, 1.8 Hz, 1ꢂCH2O), 4.28e4.19
(1H, m, CHNH), 2.03e1.79 (1H, m, CHCH3),1.09 (3H, d, J 7.2 Hz, CH3);
dC (75 MHz, CDCl3) 133.8, 116.9, 77.6, 59.7, 30.7, 9.5. Other data as
above. The X-ray diffraction data have been submitted to the
Cambridge Structural Database (Ref. number CCDC 898464).
4.4.16. Hexa-4,5-dien-1-yl sulfamate (9). Wt 445 mg; 48%; colour-
less oil; nmax/cmꢁ1 3391, 3291, 2939, 1958, 1539, 1455, 1344, 1169,
895; dH (300 MHz, CDCl3) 5.16e5.11 (1H, m, CH]), 4.92e4.66 (4H,
m, CH2] and NH2), 4.26 (2H, t, J 6.4 Hz, CH2O), 2.22e2.06 (2H, m,
CH2CH]), 1.97e1.81 (2H, m, CH2CH2CH]); dC (75 MHz, CDCl3)
208.6, 88.5, 75.7, 70.7, 27.9, 23.9; m/z (ESIþ) 178 (MþHþ, 100%), 154
(10%), 115 (10%); HRMS (ESIþ) found 178.0533, C6H12O3NS (MþH)þ
requires 178.0533.
4.4.12. 4-((Benzyloxy)methyl)-4-vinyl-1,2,3-oxathiazinane 2,2-
dioxide (5l). Wt 33 mg; 65%; colourless oil; nmax/cmꢁ1 3298,
2864, 1454, 1402, 1350, 1195, 1076, 779; dH (300 MHz, CDCl3)
7.35e7.18 (5H, m), 5.95 (1H, ddd, J 17.9, 11.1, 0.9 Hz, CH]CH2), 5.26
(1H, d, J 11.1 Hz, H of CH2]), 5.12 (1H, d, J 17.9 Hz, H of CH2]), 4.91
(1H, s, NH), 4.73e4.63 (1H, m, H of CH2OSOꢁ2 ), 4.55e4.37 (3H, m, H
of CH2OSOꢁ2 , 2ꢂH of PhCH2O), 3.33 (1H, roofed d, J 9.5 Hz, H of
CH2OBn), 3.19 (1H, roofed d, J 9.5 Hz, H of CH2OBn), 2.43 (1H, ddd, J
13.2, 4.7, 3.8 Hz, H of CH2CH2O), 1.66 (1H, dt, J 13.2, 2.1 Hz, H of
CH2CH2O); dC (75 MHz, CDCl3) 137.1, 136.7, 128.7, 128.3, 128.0, 117.1,
74.3, 73.5, 68.9, 63.0, 27.1; m/z (ESIþ) 284 (MþHþ, 100%); HRMS
(ESIþ) found 284.0955, C13H18NO4S (MþH)þ requires 284.0951.
4.5. (Z)-Ethyl 3-vinylhexa-2,5-dienoate (12)
5-Hexen-2-yn-1-ol 4u61 (2.28 g, 25.5 mmol) was dissolved in
triethyl orthoacetate (14.8 mL). Propionic acid (0.4 mL) was added
and heated to reflux under nitrogen, with a DeaneStark apparatus,
for 5 h. Reaction mixture was allowed to cool, extracted with
diethyl ether and washed with deionised water. Purification by
column chromatography (20:1 petroleum ether/ethyl acetate)
4.4.13. 4-(Methoxymethyl)-4-vinyl-1,2,3-oxathiazinane 2,2-dioxide
(5m). Wt 22 mg; 44%; colourless oil; nmax/cmꢁ1 3263, 2899, 1402,
1352,1255,1187,1114,1013, 972; dH (300 MHz, CDCl3) 6.06 (1H, dd, J
17.0 11.0 Hz, CH]CH2), 5.41e5.20 (2H, m, CH]CH2), 4.95 (1H, s,
NH), 4.83e4.67 (1H, m, 1ꢂCH2CH2O), 4.55e4.42 (1H, m,
1ꢂꢂCH2CH2O), 3.38 (3H, s, OCH3), 3.18 (2H, apparent q, J 9.4 Hz,
CH2OCH3), 2.55e2.31 (1H, m, 1ꢂCH2CH2O), 1.74 (1H, dt, J 14.7,
2.2 Hz, CH2CH2O); dC (75 MHz, CDCl3) 137.1, 117.0, 76.8, 68.8, 63.0,
59.1, 27.1; m/z (ESIþ) 284 (MþHþ, 100%); HRMS (ESIþ) found
284.0955, C13H18NO4S (MþH)þ requires 284.0951.
afforded the title compound. Wt 1.07 g; 26%; yellow tinted oil; nmax
/
cmꢁ1 2980, 1710, 1632, 1369, 1149, 1038, 998, 914, 859; dH
(400 MHz, CDCl3) 7.69 (1H, ddd, J 17.7, 11.1, 0.9 Hz, CH2]CHeC),
5.87e5.67 (1H, m, CH2CH]CH2), 5.62 (1H, s, ]CHC(O)), 5.55e5.51
(1H, m, CHtrans of alkene) 5.36 (1H, ddd, J 11.1, 1.6, 1.2 Hz, CHcis of
alkene), 5.09e4.97 (2H, m, 2ꢂCH of terminal alkenes superposed),
4.09 (2H, q, J 7.1 Hz, CH2O), 3.02 (2H, apparent dq, J 6.6, 1.2 Hz,
CeCH2eCH]), 1.20 (3H, t, J 7.1 Hz, CH3); dC (101 MHz, CDCl3) 166.0,
152.3, 134.9, 133.1, 120.2, 118.2, 117.4, 59.8, 37.4, 14.2; m/z (ESIþ) 167
(MþHþ, 100%), HRMS (ESIþ) found 167.1064, C10H15O2 (MþHþ)
requires 167.1067.
4.4.14. tert-Butyl 5-methyl-4-vinyl-1,2,3-oxathiazinane-3-
carboxylate 2,2-dioxide (7). 5-Methyl-4-vinyl-1,2,3-oxathiazinane
2,2-dioxide (188 mg, 1.0 mmol) was dissolved in dry dichloro-
methane (10 mL) and di-tert-butyl dicarbonate (255 mg, 1.2 mmol)
was added followed by pyridine (94
mL, 1.2 mmol) and dimethyla-
4.6. tert-Butyldimethyl((3-vinylidenehex-5-en-1-yl)oxy)si-
minopyridine (13 mg, 0.1 mmol). The reaction mixture was stirred
for 18 h. The reaction mixture was poured into brine (10 mL) and
extracted with dichloromethane (3ꢂ10 mL), dried (Na2SO4) and
concentrated in vacuo. Purification by column chromatography (1:1
dichloromethane/hexane to dichloromethane) afforded the title
compound. Wt 146 mg; 50%; colourless oil; nmax/cmꢁ1 3266, 2976,
1647, 1424, 1360, 1187, 920; dH (300 MHz, CDCl3) 6.02 (1H, ddd, J
17.2, 10.0, 8.4 Hz, CH]CH2), 5.46e5.27 (2H, m, CH]CH2), 4.75 (1H,
ddd, J 10.9, 4.5, 0.6 Hz, 1ꢂCH2O), 4.55 (1H, ddd, J 10.9, 6.5, 0.9 Hz,
lane (15)
5-((tert-Butyldimethylsilyl)
oxy)pent-2-yn-1-yl
4-methyl-
benzenesulfonate 1471 (11.09 g, 30.1 mmol) was dissolved in dry
THF (60 mL) under nitrogen. Copper(I) bromide (404 mg, 3 mmol)
was added. 1 M Allylmagnesium bromide (11.43 mL, 11.43 mmol)
was added dropwise and stirred for 2 h at room temperature. The
reaction was quenched with ammonium chloride and extracted
with diethyl ether. Organic layer was dried with Na2SO4 and the

736
M.C.M. Higginbotham et al. / Tetrahedron 71 (2015) 727e737
solvent was evaporated. Purification by column chromatography
(100% petroleum ether) afforded the title compound. Wt 6.21 g;
85%; yellow tinted oil; nmax/cmꢁ1 2954, 2926, 2895, 2856, 1958,
1638, 1471, 1255, 1253, 1095, 833, 773; dH (300 MHz, CDCl3)
5.86e5.55 (1H, m, CH]CH2), 5.13e4.83 (2H, m, CH2]CH),
4.70e4.52 (2H, m, CH2]C), 3.65 (2H, t, J 7.2 Hz, CH2O), 2.74e2.66
(2H, m, ]CHCH2), 2.12 (2H, tt, J 7.2, 3.0 Hz, CH2CH2O), 0.84 (9H, s,
SiC(CH3)3), 0.00 (6H, s, Si(CH3)2); dC (75 MHz, CDCl3); 206.3, 135.7,
115.9, 98.6, 75.5, 61.8, 37.4, 34.9, 25.9, 18.3, ꢁ5.3; m/z (ESIþ) 255
((MþOþH)þ, 100%), HRMS (ESIþ) found 255.1775, C14H27O2Si
(MþOþH)þ requires 255.1780.
2964, 2876, 1642, 1379, 1352, 1175; dH (300 MHz, CDCl3) 6.09 (1H,
dd, J 17.7, 11.1 Hz, CH2CH]), 5.94 (1H, dddd, J 17.1, 10.2, 6.2, 5.5 Hz,
CCH]CH2), 5.34e5.08 (4H, m, CH2] and CH2]), 4.72e4.52 (2H, m,
CH2O), 3.93 (1H, ddt, J 17.0, 5.4, 1.6 Hz, 1ꢂCH2CH]), 3.74 (1H, ddt, J
17.0, 6.2, 1.4 Hz, 1ꢂCH2CH]), 2.24e2.08 (1H, m, 1ꢂCH2CH2O),
2.05e1.68 (3H, m, 1ꢂCH2CH2O and CH2CH2CH3), 1.51e1.19 (2H, m,
CH2CH3), 0.92 (3H, t, J 7.3 Hz, CH3); dC (75 MHz, CDCl3) 139.3, 135.5,
117.1, 115.5, 68.5, 67.4, 48.3, 39.4, 31.3, 17.2, 14.3; m/z (ESIþ) 263
(M þ NHþ4 , 70%), 246 (MþHþ, 100%); HRMS (ESIþ) found 246.1162,
C
11H20O3NS (MþH)þ requires 246.1158.
4.10. 4-(Allylamino)-4-vinylheptanenitrile (20)
4.7. 3-Vinylidenehex-5-en-1-yl sulfamate (16)70
3-Allyl-4-propyl-4-vinyl-1,2,3-oxathiazinane
2,2-dioxide
tert-Butyldimethyl((3-vinylidenehex-5-en-1-yl)oxy)silane (15)
(1.76 g, 7.4 mmol) was in dissolved THF and 1 M TBAF (14.8 mL,
14.8 mmol) was added and stirred at room temperature for 4 h.
Water was added and extracted with diethyl ether. Organic layer
was dried with Na2SO4 and the solvent was evaporated giving 3-
vinylidenehex-5-en-1-ol. Wt 800.9 mg; 87%, yellow tinted oil,
was reacted on without purification. Formic acid (0.2 mL, 5.3 mmol)
was added chlorosulfonylisocyanate (0.46 mL, 5.3 mmol) at 0 ꢀC
under N2. Acetonitrile (0.4 mL) was added and allowed to
come to room temperature overnight. 3-Vinylidenehex-5-en-1-ol
(262.6 mg, 2.1 mmol) was added at 0 ꢀC and stirred for 24 h
allowing to come to room temperature gradually. Water was added
and extracted with diethyl ether. Organic layer was dried with
Na2SO4 and the solvent was evaporated. Purification by column
chromatography (1:1 petroleum ether/dichloromethane) afforded
(100 mg, 0.41 mmol) was dissolved in dry dimethylformamide
(1.4 mL) and potassium cyanide (133 mg, 2.04 mmol) was added
and stirred at 40 ꢀC for 2 days. The reaction mixture was diluted
with ether (2 mL) and H2SO4 (20% aqueous; 2 mL) was added and
stirred for 5 h. The mixture was neutralised with solid sodium
carbonate and extracted with diethyl ether (3ꢂ5 mL). The com-
bined organic phase was washed with water (ꢂ2), brine and con-
centrated in vacuo to give the title compound. Wt 61 mg; 78%;
colourless oil; nmax/cmꢁ1 3083, 2959, 2933, 2873, 2246, 1643, 1458,
1416, 918; dH (300 MHz, CDCl3) 5.90 (1H, ddt, J 17.1, 10.2, 5.8 Hz,
CH]CH2), 5.58 (1H, dd, J 17.5, 10.9 Hz, CH]CH2), 5.27e5.01 (4H, m,
]CH2 and ]CH2), 3.02 (2H, dt, J 5.8, 1.5 Hz, CH2N), 2.32 (2H, ddd, J
8.3, 6.9, 1.0 Hz, CH2CN), 1.95e1.63 (2H, m, CH2CH2CN), 1.54e1.08
(4H, m, CH2CH2CH3), 0.92 (3H, t, J 7.2 Hz, CH3); dC (75 MHz, CDCl3)
143.0, 137.0, 120.8, 115.5, 114.9, 58.5, 44.3, 39.0, 31.5, 16.4, 14.4, 11.3;
m/z (ESIþ) 193 (MþHþ, 100%); HRMS (ESIþ) found 193.1695,
the title compound. Wt 138.9 mg; 33%; caramel coloured oil; nmax
/
cmꢁ1 3380, 3285, 3076, 2979, 2902, 1958, 1638, 1556, 1359, 1176,
973, 911; dH (400 MHz, CDCl3) 5.82 (1H, ddt, J 16.9,10.1, 6.8 Hz, CH]
CH2), 5.18e5.05 (2H, m, CH]CH2), 4.99 (2H, s, NH2), 4.83e4.79 (2H,
m, CH2]C), 4.32 (2H, t, J 7.0 Hz, CH2O), 2.85e2.67 (2H, m,
CH2CH]), 2.46e2.37 (2H, m, CH2CH2O); dC (101 MHz, CDCl3) 205.9,
135.0, 116.7, 97.1, 77.1, 69.3, 37.3, 30.5.
C
12H21N2 (MþH)þ requires 193.1699.
4.11. (E)-N-(1-Allyl-5-propyl-5-vinylpyrrolidin-2-ylidene)
acetamide (21)
Under an inert atmosphere (nitrogen), diisopropylethylamine
(134 mg, 180
4-vinylheptanitrile in dry dichloromethane (2.2 mL). The reaction
mixture was cooled to 0 ꢀC and acetic anhydride (32 mg, 29
L,
ml, 1.04 mmol) was added dropwise to 4-(allylamino)-
4.8. 2-(Bicyclo[3.1.0]hex-2-en-1-yl)ethyl sulfamate (17)
m
3-Vinylidenehex-5-en-1-yl sulfamate (16) (42.7 mg, 0.24 mmol)
was dissolved in CDCl3. [Bis(trifluoromethanesulfonyl)imidate]
(triphenylphosphine)gold(I) (2:1) toluene adduct (18.9 mg,
0.012 mmol) was added under N2. Purification by column chro-
matography (1:1 petroleum ether/dichloromethane) afforded the
title compound. Wt 21.5 mg; 51%; clear oil; nmax/cmꢁ1 3366, 3281,
3057, 2983, 2903, 2837, 2360, 1577, 1360, 1179, 907; dH (400 MHz,
CDCl3) 5.73e5.66 (1H, m, ]CHeCH2), 5.35e5.25 (1H, m, ]CHeC),
4.72 (2H, s, NH2), 4.17 (2H, dd, J 7.3 6.6 Hz, CH2eO), 2.51 (1H, dd, J
17.9, 7.0 Hz, H of allylic CH2), 2.18 (1H, apparent dt, J 17.9, 2.4 Hz, H
of allylic CH2), 2.00 (1H, dt, J 14.5, 6.6 Hz, H of CH2eCH2O), 1.75 (1H,
dt, J 14.5, 7.3 Hz, H of CH2CH2O), 1.37e1.28 (1H, m, CH2CHCH2),
0.72e0.66 (1H, m, H of cyclopropyl CH2), 0.04-(-0.02) (1H, m, H of
cyclopropyl CH2); dC (101 MHz, CDCl3); 135.8, 128.1, 70.8, 36.2, 32.7,
32.6, 21.9, 21.1; m/z (ESIþ) 221 ((MþNH4)þ, 100%), HRMS (ESIþ)
found 221.0954, C8H17N2O3S (MþNH4)þ requires 221.0960.
0.31 mmol) was added dropwise followed by dimethylaminopyr-
idine (32 mg, 0.26 mmol). The reaction mixture was heated to
reflux for 48 h. The room temperature reaction mixture was
quenched with water (2 mL) followed by H3PO4 (5% wt/v; 1 mL) and
the organic layer was separated. The aqueous layer was further
extracted with dichloromethane (2ꢂ5 mL) and the combined or-
ganic phase was washed with saturated sodium bicarbonate solu-
tion and dried (Na2SO4) and concentrated in vacuo. Purification by
column chromatography (1:1 petroleum ether/ethyl acetate)
afforded the title compound. Wt 24 mg; 43%; yellow oil; nmax/cmꢁ1
2961, 2875, 1642, 1540, 1263, 1249, 990, 925; dH (400 MHz, CDCl3)
5.90 (1H, dddd, J 17.1, 10.2, 6.9, 4.7 Hz, ]CHCH2N), 5.78 (1H, dd, J
17.4, 10.8 Hz, ]CHC), 5.20e5.00 (4H, m, ]CH2 and ]CH2), 4.09
(1H, dd, J 15.3, 4.7 Hz, 1ꢂCH2N), 3.69 (1H, dd, J 15.3, 6.9 Hz,
1ꢂCH2N), 3.13e2.94 (1H, m, 1ꢂCH2C]N), 2.94e2.76 (1H, m,
1ꢂCH2C]N), 2.14 (3H, s, CH3C]O), 1.95 (2H, t,
J 7.9 Hz,
CH2CH2CH3), 1.72 (1H, ddd, J 13.7, 12.1, 5.0 Hz, 1ꢂCH2C), 1.58 (1H,
ddd, J 13.7, 12.1, 4.4 Hz, 1ꢂCH2C), 1.43e1.05 (2H, m, CH2CH3), 0.92
(3H, t, J 7.3 Hz, CH3); dC (100 MHz, CDCl3) 184.3, 170.1, 140.1, 133.7,
117.1, 114.7, 69.3, 44.8, 38.9, 31.6, 29.1, 28.0, 17.0, 14.3; m/z (ESIþ) 235
(MþHþ, 100%), 194 (70%); HRMS (ESIþ) found 235.1806, C14H23ON2
(MþH)þ requires 235.1805.
4.9. 3-Allyl-4-propyl-4-vinyl-1,2,3-oxathiazinane 2,2-dioxide
(19)
To a stirring solution of 4-propyl-4-vinyl-1,2,3-oxathiazinane
2,2-dioxide (735 mg, 3.6 mmol) in dichloromethane (26 mL) were
added benzyltributylammonium bromide (64 mg, 179 mmol), allyl
bromide (1.2 mL, 14.3 mmol) and sodium hydroxide solution (5 M).
The reaction mixture was stirred for 24 h. Purification by column
chromatography (4:1 petroleum ether/ethyl acetate) afforded the
title compound. Wt 728 mg; 84%; colourless oil; nmax/cmꢁ1 3087,
Acknowledgements
The authors thank the Engineering and Physical Sciences Re-
search Council (for a DTA to M.C.M.H. and for funding to L.K. (Grant

M.C.M. Higginbotham et al. / Tetrahedron 71 (2015) 727e737
737
29. Fluxionality of a Au(I)eallene complex: Brown, T. J.; Sugie, A.; Leed, M. G. D.;
Widenhoefer, R. A. Chem.dEur. J. 2012, 18, 6959.
EP/J006602/01)), the EPSRC National Mass Spectrometry Facility for
mass spectra, the Leverhulme Trust (for funding to A.G.L. (grant no.
F00/276/Q)), the EU (for an ERASMUS exchange studentship for
A.T.), Dr. G.M. Rosair for assistance with X-ray crystallography and
Dr. A.-L. Lee for helpful discussions.
30. There is some variation in the literature regarding nomenclature for amines of
this type. ‘N-substituted quaternary centres’ is commonplace in a number of
papers and is used here for continuity but is not strictly correct. N-(C-Tertiary)
amines or tertiary carbinamines have also been suggested and are more in line
with IUPAC nomenclature, but given the prevalence of the first term in the
existing literature, we have elected to persist with the term we used in our
original communication.
31. Kinder, R. E.; Zhang, Z.; Widenhoefer, R. A. Org. Lett. 2008, 10, 3157.
32. Winter, C.; N. Krause, N. Angew. Chem., Int. Ed. 2009, 48, 6339.
33. Lalonde, R. L.; Wang, Z. J.; Mba, M.; Lackner, A. D.; Toste, F. D. Angew. Chem., Int.
Ed. 2010, 49, 598.
Supplementary data
1H and 13C NMR spectra for all new compounds. Crystallo-
graphic data (excluding structure factors) for cis-5a and cis-5g have
been deposited with the Cambridge Crystallographic Data Centre as
supplementary publication numbers CCDC 871548 and CCDC
898464, respectively. Copies of the data can be obtained, free of
charge, on application to CCDC, 12 Union Road, Cambridge CB2 1EZ,
UK (fax:þ44 (0)1223 336033 or email:deposit@ccdc.cam.ac.uk).
Supplementary data associated with this article can be found in the
online version, at http://dx.doi.org/10.1016/j.tet.2014.11.058.
34. Shibasaki, M.; Kanai, M. Chem. Rev. 2008, 106, 2853.
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36. Pradal, A.; Toullec, P. Y.; Michelet, V. Synthesis 2011, 1501.
37. Wang, Y.-M.; Lackner, A. D.; Toste, F. D. Acc. Chem. Res. 2014, 47, 889.
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