Science - USA (2021-11-05)

requires biocatalysts to overcome the energy
barrier in the aqueous environment, whereas
the mechanism reported here was spontane-
ous during surface solvation. This surprising
finding adds to the current understanding of
heterogeneous surface chemistry and creates
new challenges for further investigations.

REFERENCES AND NOTES

1. C. George, M. Ammann, B. D’Anna, D. J. Donaldson,
   S. A. Nizkorodov,Chem. Rev. 115 , 4218–4258 (2015).


2. T. Huthwelker, M. Ammann, T. Peter,Chem. Rev. 106 ,
   1375 – 1444 (2006).


3. W. R. Simpson, S. S. Brown, A. Saiz-Lopez, J. A. Thornton,
   R. von Glasow,Chem. Rev. 115 , 4035–4062 (2015).


4. J. B. Burkholder, R. A. Cox, A. R. Ravishankara,Chem. Rev. 115 ,
   3704 – 3759 (2015).


5. C. Hoose, O. Möhler,Atmos. Chem. Phys. 12 , 9817– 9854
   (2012).


6. M. E. Wise, S. T. Martin, L. M. Russell, P. R. Buseck,Aerosol
   Sci. Technol. 42 , 281–294 (2008).


7. X. Konget al.,J. Phys. Chem. C 124 , 5263–5269 (2020).


8. D. A. Bruzewiczet al.,J. Chem. Phys. 134 , 044702
   (2011).


9. H. Hansen-Goos, E. S. Thomson, J. S. Wettlaufer,Planet. Space
   Sci. 98 , 169–181 (2014).


10. D. Castarède, E. S. Thomson,Atmos. Chem. Phys. 18 ,
    14939 – 14948 (2018).


11. M. T. C. Martins-Costa, J. M. Anglada, J. S. Francisco,
    M. F. Ruiz-López,J. Am. Chem. Soc. 142 , 20937– 20941
    (2020).


12. G. Wanget al.,Proc. Natl. Acad. Sci. U.S.A. 113 , 13630– 13635
    (2016).


13. R. J. Huanget al.,Nature 514 , 218–222 (2014).


14. A. V. Naumkin, A. Kraut-Vass, C. J. Powell, NIST Standard
    Reference Database 20, Version 3.4, NIST X-ray Photoelectron
    Spectroscopy Database (National Institute of Standards and
    Technology, 2003); https://srdata.nist.gov/xps/.


15. C.F.Fu,S.X.Tian,J. Phys. Chem. C 117 , 13011– 13020
    (2013).


16. Y. M. Shul’gaet al.,Synth. Met. 70 , 1381–1382 (1995).


17. F. Fdz-Polancoet al.,Water Sci. Technol. 44 , 77– 84
    (2001).


18. E. Rikmannet al.,Biodegradation 23 , 509–524 (2012).


19. F. Fdz-Polancoet al.,Water Res. 35 , 1111–1114 (2001).


20. P. Hvelplundet al.,J. Phys. Chem. A 114 , 7301– 7310
    (2010).


21. C. A. Colberg, B. P. Luo, H. Wernli, T. Koop, T. Peter,
    Atmos. Chem. Phys. 3 , 909–924 (2003).


22. J. Turšič, A. Berner, B. Podkrajšek, I. Grgić,Atmos. Environ. 38 ,
    2789 – 2795 (2004).


23. M. Kumar, J. S. Francisco,Proc. Natl. Acad. Sci. U.S.A. 114 ,
    864 – 869 (2017).


24. Y. Suleymanov,Science 371 , 139 (2021).


25. J. P. D. Abbattet al.,Science 313 , 1770–1773 (2006).


26. J. E. Shilling, T. J. Fortin, M. A. Tolbert,J. Geophys. Res. 111 ,
    D12204 (2006).


27. D. J. Cziczo, J. P. D. Abbatt,J. Geophys. Res. 104 ,
    13781 – 13790 (1999).


28. K. J. Baustian, M. E. Wise, M. A. Tolbert,Atmos. Chem. Phys.
    10 , 2307–2317 (2010).


29. X. R. Konget al.,Tellus B 70 , 1463806 (2018).


30. S. Tanuma, C. J. Powell, D. R. Penn,Surf. Interface Anal. 21 ,
    165 – 176 (1994).


31. N. Ottosson, M. Faubel, S. E. Bradforth, P. Jungwirth,
    B. Winter,J. Electron Spectrosc. Relat. Phenom. 177 , 60– 70
    (2010).


32. X. Konget al., Data for“A surface-promoted redox reaction
    occurs spontaneously on solvating inorganic aerosol
    surfaces,”Version 2, Zenodo (2021); https://doi.org/10.5281/
    zenodo.5222334.

ACKNOWLEDGMENTS
X.K. thanks P. Corral Arroyo for inspiring discussions during the
beamtime at the SLS. I.G. thanks F. Pietrucci, F. Jensen, and
M. Carignano for fruitful discussions.Funding:This work is
supported by the Swedish Research Council VR (2015-04212). X.K.
acknowledges support from the National Natural Science
Foundation of China (41975160) and the Swedish Foundation for
International Cooperation in Research and Higher Education

(CH2019-8361). E.S.T. is supported by the Swedish Research

Councils Formas (2017-00564) and VR (2020-03497) and by the

Swedish Strategic Research Area MERGE. For high-performance

computing (HPC) resources and services, we acknowledge the

Research Computing group at Texas A&M University at Qatar,

founded by the Qatar Foundation for Education, Science and

Community Development, and use of Qatar Environment and

Energy Research Institute (QEERI) HPC under Project ID

HPC-P20003.Author contributions:X.K., E.S.T., and J.B.C.P.

initialized the concept. X.K. analyzed the data and wrote the

experimental part of the paper. I.G. performed the calculations and

wrote the theoretical part of the paper. X.K., L.A., and E.S.T.

coordinated the beamtime. X.K., D.C., A.B., and E.S.T. carried out

the beamtime experiments. L.A. and M.A. supported the beamtime

and data analysis. All authors discussed the results and contributed

to data interpretation and paper revisions.Competing interests:

None declared.Data and materials availability:All data needed to

evaluate the conclusions in this paper are present in the paper or in

the supplementary materials. All data presented in this paper are

deposited at Zenodo ( 32 ).

SUPPLEMENTARY MATERIALS

science.org/doi/10.1126/science.abc5311

Materials and Methods

Supplementary Text

Figs. S1 to S15

Tables S1 to S3

References ( 33 Ð 73 )

Movies S1 to S5

7 December 2020; resubmitted 14 July 2021

Accepted 19 August 2021

10.1126/science.abc5311

ORGANIC CHEMISTRY

Enantioselective catalytic 1,2-boronate rearrangements

Hayden A. Sharma†, Jake Z. Essman†, Eric N. Jacobsen*

A strategy that facilitates the construction of a wide variety of trisubstituted stereocenters through

a catalytically accessed common chiral intermediate could prove highly enabling for the field of

synthetic chemistry. We report the discovery of enantioselective, catalytic 1,2-boronate rearrangements

for the synthesis ofa-chloro pinacol boronic esters from readily available boronic esters and

dichloromethane. The chiral building blocks produced in these reactions can undergo two sequential

stereospecific elaborations to generate a wide assortment of trisubstituted stereocenters. The

enantioselective reaction is catalyzed by a lithium-isothiourea-boronate complex, which is proposed to

promote rearrangement through a dualÐlithium-induced chloride abstraction orchestrated by Lewis

basic functionality on the catalyst scaffold.

O

rganoboron compounds are valuable re-

agents for the synthesis of a wide variety

of molecules with useful biological or

material properties ( 1 – 4 ). In particular,

the stereospecific elaboration of enan-

tioenriched alkylboron reagents is a power-

ful strategy for the construction of molecules

bearing carbon- and heteroatom-substituted

stereocenters ( 5 – 7 ). Many of these elaboration

reactions leverage the characteristic reactivity

of tetracoordinate boronate derivatives bearing

a-leaving groups, which are prone to 1,2-

rearrangement pathways that are stereoinver-

tive at the carbon bearing the leaving group

and stereoretentive at the migrating carbon

(Fig. 1A). These rearrangements find sub-

stantial utility in stereoselective synthesis,

as exemplified by the venerable Matteson

homologation reaction in which boronic esters

undergo a one-carbon chain extension via the

formation and rearrangement of dichloromethyl-

substituted boronates (Fig. 1B) ( 8 – 10 ). This

process can be rendered stereoselective through

the use of chiral diol auxiliaries on boron. The

a-chloro boronic ester products of these di-

astereoselective rearrangement reactions are

configurationally stable and can undergo a

second nucleophilic addition and rearrange-

ment with high stereospecificity to afford a

variety of chiral secondary boronic esters bear-

ing chiral diol substitution on boron.

We envisioned that the development of a

catalytic, enantioselective rearrangement of

pinacol-substituted dichloromethyl boronates

could form the basis for a modular and high-

ly general strategy for the synthesis of tri-

substituted stereocenters. Such a reaction

would afford chiral building blocks bearing

chlorine and pinacol boronic ester substitu-

ents on a defined stereogenic carbon center

( 11 ) that could be elaborated enantiospecifi-

cally through a second rearrangement sequence

and a carbon-boron bond transformation (Fig.

1C). In addition to requiring only catalytic

levels of a chiral source to achieve absolute

stereocontrol, this strategy would leverage

recent, powerful methods for the elaboration

of carbon-boron bonds that primarily make

use of pinacol boronic esters ( 5 ). The catalytic,

enantiodetermining event would involve com-

mitment to only one of the three ultimate sub-

stituents, thereby enabling immense versatility

and potential generality in the enantioselective

construction of trisubstituted carbon stereo-

centers from dichloromethane as the common

starting material. Here, we report the dis-

covery of a catalytic method for controlling

752 5 NOVEMBER 2021•VOL 374 ISSUE 6568 science.orgSCIENCE

Department of Chemistry and Chemical Biology, Harvard

University, Cambridge, MA 02138, USA.

*Corresponding author. Email: [email protected]

†These authors contributed equally to this work.

RESEARCH | REPORTS