Ring expansion of cyclic 1,2-diols to form medium sized rings via ruthenium catalyzed transfer hydrogenative [4+2] cycloaddition

Article abstract of DOI:10.1039/c4cc03983a

A new method for the ring expansion of cyclic diols is described. Using improved conditions for the ruthenium(0) catalyzed cycloaddition of cyclic 1,2-diols with 1,3-dienes, fused [n.4.0] bicycles 3a-3r (n = 3-6) are formed, which upon exposure to iodosobenzene diacetate engage in oxidative cleavage to form the 9-12 membered rings 4a-4r. the Partner Organisations 2014.

Full text of DOI:10.1039/c4cc03983a

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Ring expansion of cyclic 1,2-diols to form
medium sized rings via ruthenium catalyzed
transfer hydrogenative [4+2] cycloaddition†
Cite this: Chem. Commun., 2014,
50, 7545
Received 21st April 2014,
Accepted 28th May 2014
Zachary A. Kasun, Laina M. Geary and Michael J. Krische*
DOI: 10.1039/c4cc03983a
www.rsc.org/chemcomm
A new method for the ring expansion of cyclic diols is described. Using
improved conditions for the ruthenium(0) catalyzed cycloaddition of
cyclic 1,2-diols with 1,3-dienes, fused [n.4.0] bicycles 3a–3r (n = 3–6)
are formed, which upon exposure to iodosobenzene diacetate engage
in oxidative cleavage to form the 9–12 membered rings 4a–4r.
Our laboratory has developed a suite of catalytic C–C bond
formations that enable direct alcohol C–H functionalization.1
These transformations operate through two principal modes of
reactivity. In initial work employing iridium2 or ruthenium(II)3
precatalysts, hydrogen exchange between primary alcohols and
p-unsaturated reactants serves to generate aldehyde–organo-
Scheme 1 Synthesis of 9–12 membered macrocyclic 1,6-diketones via
ruthenium(0) catalyzed diol–diene [4+2] cycloaddition.
metal pairs en route to products of carbonyl addition.2,3 In more bridgehead hydroxyl moieties, should readily undergo oxida-
recent work using ruthenium(0) precatalysts derived from Ru3(CO)12, tive cleavage to form the corresponding 9–12 membered
pathways involving secondary alcohol mediated transfer hydro- 1,6-diketones 4a–4o.6,9 Beyond broadening access to medium
genolysis of oxometallacycles derived upon ketone-unsaturate sized rings, this exercise would provide a valuable opportunity
oxidative coupling are operative.4 Based on the latter reactivity to refine and further explore the capabilities of the key transfer
mode, conjugated dienes were found to engage vicinal diols by hydrogenative cycloaddition methodology.5 For example, as our
way of their corresponding 1,2-diones to form products of formal initially reported conditions for cycloaddition employ BIPHEP
[4+2] cycloaddition.5 In this account, we disclose a concise ($475 USD per 5 g),10 a rather expensive ligand, an effort was
synthesis of medium sized (9–12 membered) 1,6-diketones via made to identify low-cost ligands that display equal or superior
ruthenium(0) catalyzed diol–diene [4+2] cycloaddition followed levels of performance.
by iodosobenzene diacetate, PhI(OAc)2, mediated oxidative cleavage
In the event, it was found that the reaction of cycloalkane
diols 1a–1e with 1,3-dienes 2a–2c could be performed efficiently
of the resulting fused [n.4.0] bicycles (Scheme 1).6
Medium sized rings play a central role in fragrance using rac-BINAP ($98 USD per 5 g)10 or dppp ($60 USD per 10 g)10
chemistry,7 and are useful building blocks in asymmetric as ligand to deliver cycloadducts 3a–3o (Table 1). Nine of
synthesis.8 It was reasoned that medium sized rings could be the fifteen cycloadducts were previously unreported, and for
accessed from abundant and inexpensive reactants, cyclo- the six known cycloadducts use of rac-BINAP or dppp provided
alkane diols 1a–1e and 1,3-dienes 2a–2c, using a [4+2] cyclo- comparable or, in most cases, better isolated yields than those
addition recently developed in our laboratory,5 as the anticipated obtained using BIPHEP. Notably, a relatively short reaction
products of cycloaddition 3a–3o, fused [n.3.0] bicycles possessing time was observed in the cycloaddition to form 3m (4 h), which
may be attributed to acceleration of the oxidative coupling of
Department of Chemistry and Biochemistry, University of Texas at Austin, Austin,
TX 78712, USA. E-mail: mkrische@mail.utexas.edu; Fax: +1 613 9418447;
Tel: +1 512 2325892
butadiene 2a to the transient 1,2-dione due to the LUMO
lowering s-inductive effect of the ether oxygen. Inspired
by this finding, the cycloaddition of diols 1f and 1g, which
are derived from D-glucose, with butadiene 2a were explored.
The cycloaddition of diols 1f delivered the cycloadduct 3p in
96% yield as an equimolar mixture of diastereomers (eqn (1)).
† Electronic supplementary information (ESI) available: Characterization data for
all new compounds (1H NMR, 13C NMR, IR, MS). Single crystal X-ray diffraction
data for compound 4r. CCDC 1000541 and 998373. For ESI and crystallographic
data in CIF or other electronic format see DOI: 10.1039/c4cc03983a
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Table 1 Ruthenium(0) catalyzed reaction of cycloalkane diols 1a–1e with
dienes 2a–2c to form products of [4+2] cycloaddition 3a–3oa
Table 2 Oxidative cleavage of cycloadducts 3a–3o mediated by iodoso-
benzene diacetate to form the 9–12 membered 1,6-diketones 4a–4oa
a
Yields are of material isolated by silica gel chromatography and
a
1a, n = 1, X = CH2; 1b, n = 2, X = CH2; 1c, n = 3, X = CH2; 1d, n = 4, X =
represent the average of two runs. See ESI for further details.
CH2, 1e, n = 1, X = O; 2a, R = H; 2b, R = Me; 2c, R = (CH2)2CHQCMe2.
Yields are of material isolated by silica gel chromatography. The cis-
1,2-diol was employed. 10 mol% 3,5-Me2BzOH added, 7 h. 10 mol%
3,5-Me2BzOH added, (2c, 400 mol%). The trans-1,2-diol was
employed. (2c, 300 mol%). 10 mol% 3,5-Me2BzOH added, 18 h,
(2c, 400 mol%). 4 h, 5 : 1 mixture of olefin regioisomers. 8 h, 14 : 1
mixture of olefin regioisomers. See ESI for further details.
b
c
d
conditions that avoid isomerization of the resulting b,g-unsaturated
ketones to the conjugated enones. Recently reported conditions
employing iodosobenzene diacetate, PhI(OAc)2, proved especially
simple, mild and effective.6 Upon exposure of cycloadducts 3a–3o
to PhI(OAc)2 in dichloromethane solvent at room temperature, the
9–12 membered 1,6-diketones 4a–4o were generated in good to
excellent yield without any isomerization to the conjugated enones
(Table 2). As illustrated in the conversion of cycloadducts 3p and 3q
to the 10-membered 1,6-diketones 4p and 4q (eqn (3) and (4)),
respectively, these conditions also were effective in more complex
settings. To further illustrate the unique features of this ring
expansion protocol, cyclohexane tetraol 1h was subjected to double
cycloaddition employing butadiene 2a, which delivers tricycle 3r in
a remarkable 92% yield, followed by iodosobenzene diacetate
mediated oxidative cleavage to form 4r (eqn (5)). The structure
of 4r was corroborated by single crystal X-ray diffraction analysis.
e
f
g
h
i
For the more highly oxygenated diol 1g, the cycloadduct 3q is
obtained in 48% yield as 3 : 1 mixture of diastereomers (eqn (2)).
(1)
(2)
(3)
With cycloadducts 3a–3q in hand, conditions for diol oxida-
tive cleavage were explored. Here, it was important to identify
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2 For iridium catalyzed C–C coupling of primary alcohols to 1,3-dienes,
allenes and 1,3-enynes, see: (a) J. F. Bower, E. Skucas, R. L. Patman
and M. J. Krische, J. Am. Chem. Soc., 2007, 129, 15134; (b) J. F. Bower,
R. L. Patman and M. J. Krische, Org. Lett., 2008, 10, 1033;
(c) J. R. Zbieg, T. Fukuzumi and M. J. Krische, Adv. Synth. Catal.,
2010, 352, 2416; (d) L. M. Geary, S. K. Woo, J. C. Leung and
M. J. Krische, Angew. Chem., Int. Ed., 2012, 51, 2972.
(4)
3 For ruthenium(II) catalyzed C–C coupling of primary alcohols to
1,3-dienes, allenes and 1,3-enynes, see: (a) F. Shibahara, J. F. Bower
and M. J. Krische, J. Am. Chem. Soc., 2008, 130, 6338; (b) F. Shibahara,
J. F. Bower and M. J. Krische, J. Am. Chem. Soc., 2008, 130, 14120;
(c) R. L. Patman, V. M. Williams, J. F. Bower and M. J. Krische, Angew.
Chem., Int. Ed., 2008, 47, 5220; (d) J. R. Zbieg, E. L. McInturff and
M. J. Krische, Org. Lett., 2010, 12, 2514; (e) J. R. Zbieg, E. L. McInturff,
J. C. Leung and M. J. Krische, J. Am. Chem. Soc., 2011, 133, 1141;
( f ) J. R. Zbieg, J. Moran and M. J. Krische, J. Am. Chem. Soc., 2011,
133, 10582; (g) J. R. Zbieg, E. Yamaguchi, E. L. McInturff and
M. J. Krische, Science, 2012, 336, 324; (h) E. L. McInturff,
E. Yamaguchi and M. J. Krische, J. Am. Chem. Soc., 2012, 134, 20628.
4 For ruthenium(0) catalyzed C–C coupling of secondary alcohols to
1,3-dienes, acrylic esters and simple olefins, see: (a) J. C. Leung,
L. M. Geary, T.-Y. Chen, J. R. Zbieg and M. J. Krische, J. Am. Chem.
Soc., 2012, 134, 15700; (b) T.-Y. Chen and M. J. Krische, Org. Lett.,
2013, 15, 2994; (c) B. Y. Park, T. P. Montgomery, V. J. Garza and
M. J. Krische, J. Am. Chem. Soc., 2013, 135, 16320; (d) E. L. McInturff,
J. Mowat, A. R. Waldeck and M. J. Krische, J. Am. Chem. Soc., 2013,
135, 17230; (e) E. Yamaguchi, J. Mowat, T. Luong and M. J. Krische,
Angew. Chem., Int. Ed., 2013, 52, 8428; ( f ) E. L. McInturff,
K. D. Nguyen and M. J. Krische, Angew. Chem., Int. Ed., 2014,
53, 3232.
(5)
In summary, we report a novel method for the ring expansion
of cycloalkane diols to form 9–12 membered 1,6-diketones. This
ring expansion protocol takes advantage of recently reported
ruthenium catalyzed transfer hydrogenative diol–diene [4+2]
cycloaddition to form fused [n.4.0] bicycles that are subject to
iodosobenzene diacetate mediated oxidative cleavage. Future
studies will focus on the developed of related C–C bond forming
transfer hydrogenations including the redox triggered C–C
coupling of amines.
Acknowledgment is made to the Robert A. Welch Founda-
tion (F-0038), the NIH-NIGMS (RO1-GM069445) and the UT
Austin Center for Green Chemistry and Catalysis for partial
support of this research.
5 For ruthenium(0) catalyzed diol–diene [4+2] cycloaddition, see:
L. M. Geary, B. W. Glasspoole, M. M. Kim and M. J. Krische,
J. Am. Chem. Soc., 2013, 135, 3796.
6 K. C. Nicolaou, V. A. Adsool and C. R. H. Hale, Org. Lett., 2010,
12, 1552.
7 For selected reviews on fragrance chemistry, see: (a) G. Ohloff, Helv.
´
Chim. Acta, 1992, 75, 2041; (b) G. Frater, J. A. Bajgrowicz and P. Kraft,
Tetrahedron, 1998, 54, 7633; (c) P. Kraft, J. A. Bajgrowicz, C. Denis
´
and G. Frater, Angew. Chem., Int. Ed., 2000, 39, 2980; (d) M. Gautschi,
J. A. Bajgrowicz and P. Kraft, Chimia, 2001, 55, 379.
8 For example, transannular asymmetric aldol reactions of macro-
cyclic diketones are used to form triquinane natural products and
(R)-muscone, respectively, see: (a) C. L. Chandler and B. List,
J. Am. Chem. Soc., 2008, 130, 6737; (b) O. Knopf, J. Kuhne and
C. Fehr, Angew. Chem., Int. Ed., 2007, 46, 1307; (c) C. Fehr,
A. K. Buzas, O. Knopff and J.-Y. de Saint Laumer, Chem. – Eur. J.,
2010, 16, 2487.
Notes and references
1 For reviews on C–C bond forming hydrogenation and transfer
hydrogenation, see: (a) J. F. Bower, I. S. Kim, R. L. Patman and
M. J. Krische, Angew. Chem., Int. Ed., 2009, 48, 34; (b) J. F. Bower and
M. J. Krische, Top. Organomet. Chem., 2011, 34, 107; (c) A. Hassan
and M. J. Krische, Org. Process Res. Dev., 2011, 15, 1236;
(d) J. Moran and M. J. Krische, Pure Appl. Chem., 2012, 84, 1729;
(e) A.-M. R. Dechert-Schmitt, D. C. Schmitt, X. Gao, T. Itoh and
M. J. Krische, Nat. Prod. Rep., 2014, 31, 504.
9 M. Shibuya, T. Shibuta, H. Fukuda and Y. Iwabuchi, Org. Lett., 2012,
14, 5010 and references cited therein.
10 Prices from Strem Chemicals, April, 2014.
This journal is ©The Royal Society of Chemistry 2014
Chem. Commun., 2014, 50, 7545--7547 | 7547