Organometallics
Communication
Scheme 5
ASSOCIATED CONTENT
* Supporting Information
Text, figures, and CIF files giving experimental details and
structural data. This material is available free of charge via the
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AUTHOR INFORMATION
Corresponding Author
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Author Contributions
†X-ray crystal structure analyses.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
Financial support from the Deutsche Forschungsgemeinschaft
is gratefully acknowledged.
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REFERENCES
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Figure 3. Molecular structure of compound 12. Selected bond lengths
(Å) and angles (deg): C1−C2 = 1.337(3), C1−S1 = 1.800(2), 2−B1 =
1.631(3), C4−S1 = 1.786(3), C3−C4 = 1.332(4), B1−C3 = 1.602(3);
C2−B1−C3 = 111.4(2), C1−S1−C4 = 107.9(1).
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S/B addition of the FLP 8c to the acetylene reagent. The
structure contains a borate anion moiety and a sulfonium unit
with a trigonal-pyramidal geometry (sum of the C−S−C
angles: 312.0°).
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We had previously shown that the advanced 1,1-carbobora-
tion reaction using B(C6F5)3 and related reagents proceeded
rapidly with substrates that featured good migrating groups at
an acetylenic terminus, such as hydride, silyl, group 4
metallocene (and possibly other typical “Wrackmeyer sub-
stituents” as well), and −PR2 groups.14 1,1-Carboboration
reactions of phosphinoalkynes were shown to likely involve
specially stabilized zwitterionic phosphirenium−borate inter-
mediates on the way.9,15 This work now has amended this
series by the −SR migrating groups. The 1,1-carboboration
reaction with −SR migration along the acetylenic framework
seems useful, since it provides an easy entry to borylated
thioenol ethers and ketene dithioacetals which themselves will
provide useful synthetic building blocks and will serve as
interesting new vicinal frustrated Lewis pairs.
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2011, 47, 10482−10484.
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dx.doi.org/10.1021/om400016t | Organometallics 2013, 32, 384−386