Tying a Molecular Overhand Knot of Single Handedness and Asymmetric Catalysis with the Corresponding Pseudo-D3-Symmetric Trefoil Knot.
We report the stereoselective synthesis of a left-handed trefoil knot from a tris(2,6-pyridinedicarboxamide) oligomer with six chiral centers using a lanthanide(III) ion template. The oligomer folds around the lanthanide ion to form an overhand knot complex of single handedness. Subsequent joining of the overhand knot end groups by ring-closing olefin metathesis affords a single enantiomer of the trefoil knot in 90% yield. The knot topology and handedness were confirmed by NMR spectroscopy, mass spectrometry, and X-ray crystallography. The pseudo-D3-symmetric knot was employed as an asymmetric catalyst in Mukaiyama aldol reactions, generating enantioselectivities of up to 83:17 er, which are significantly higher than those obtained with a comparable unknotted ligand complex.
School of Chemistry, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
Guzmán
G
Gil-Ramírez
School of Chemistry, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
Steven
S
Hoekman
School of Chemistry, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
Matthew O
MO
Kitching
School of Chemistry, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
David A
DA
Leigh
School of Chemistry, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
Iñigo J
IJ
Vitorica-Yrezabal
School of Chemistry, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
Gen
G
Zhang
Angew Chem Int Ed Engl. 2014 Jul 21;53(30):7823-7
24899408
J Org Chem. 2012 Jul 6;77(13):5624-32
22697304
Dalton Trans. 2011 Dec 7;40(45):12056-9
21938292
Chem Sci. 2016 Apr 21;7(4):2524-2531
28660022
J Am Chem Soc. 2015 Aug 19;137(32):10437-42
26214819
Chem Commun (Camb). 2013 Sep 25;49(74):8157-9
23925587
J Am Chem Soc. 2012 Jun 6;134(22):9488-97
22554153
J Am Chem Soc. 2014 Sep 24;136(38):13142-5
25198065
Angew Chem Int Ed Engl. 2013 Sep 16;52(38):9956-60
23832610
Angew Chem Int Ed Engl. 2014 Oct 20;53(43):11463-6
24989322
J Am Chem Soc. 2013 Sep 18;135(37):13972-9
24006879
Chem Rev. 2011 Sep 14;111(9):5434-64
21692460
Nat Chem. 2010 Mar;2(3):156-7
21124466
Chem Commun (Camb). 2014 Mar 18;50(22):2857-60
24496247
J Am Chem Soc. 2011 Jul 20;133(28):10764-7
21688784
Chem Soc Rev. 2013 Feb 21;42(4):1700-12
22890502
PLoS Comput Biol. 2006 Sep 15;2(9):e122
16978047
J Am Chem Soc. 2015 Aug 12;137(31):9812-5
26148842
Angew Chem Int Ed Engl. 2004 Aug 27;43(34):4482-5
15340949
Angew Chem Int Ed Engl. 2006 Aug 25;45(34):5698-702
16856201
Chemistry. 2013 Nov 25;19(48):16181-6
24174126
Org Lett. 2002 Jan 24;4(2):301-3
11796075
Nat Chem. 2010 Mar;2(3):218-22
21124480
Nat Chem. 2016 Apr 22;8(5):404-6
27102672
Angew Chem Int Ed Engl. 2007;46(1-2):254-9
17031890
Science. 2016 Jun 24;352(6293):1555-9
27339983
Chem Soc Rev. 2005 Dec;34(12):1048-77
16284671
Org Lett. 2001 Aug 9;3(16):2543-6
11483056
Angew Chem Int Ed Engl. 2012 May 7;51(19):4747-50
22474006
J Am Chem Soc. 2014 Jun 11;136(23):8243-51
24831779
Angew Chem Int Ed Engl. 2000 May;39(9):1616-1618
10820452
J Phys Condens Matter. 2015 Sep 9;27(35):354101
26291690
Science. 2012 Nov 9;338(6108):783-5
23139329
J Am Chem Soc. 2007 Sep 12;129(36):10986-7
17696537
Nat Chem. 2011 Nov 06;4(1):15-20
22169866
Angew Chem Int Ed Engl. 2011 Dec 16;50(51):12280-4
21919173
Angew Chem Int Ed Engl. 2001 Jul 2;40(13):2468-2471
11443667
J Am Chem Soc. 2016 Feb 17;138(6):1749-51
26835978
Angew Chem Int Ed Engl. 2015 Nov 9;54(46):13545-9
26387887
Nature. 2001 Jun 14;411(6839):763
11459044