title: Mechanistic Insights into the Aerobic Cu(I)-Catalyzed Cross-Coupling ofS-Acyl Thiosalicylamide Thiol Esters and Boronic Acids.
abstract: The Density Functional Theory (DFT) method is used to elucidate the nature of the active species and the mechanism of the aerobic CuI-catalyzed cross-coupling of S-acyl thiosalicylamide thiol esters and boronic acids reported previously (J. Am. Chem. Soc.2007,129, 15734-15735;Angew. Chem.,Int. Ed.2009,48, 1417-1421). The energetically lowest isomer of the proposed active species [LC(O)R1]Cu-(O2)-Cu[LC(O)R1]2+,2a, (where L = thiolatosalicylamide) is found to beI1(OO,OO)with aμ-η2:η2-peroxo Cu2O2-core, while its isomersI2(OO,OO)with abis-(μ-O) Cu2O2-core andI3(OO,OO)with a (μ-η1:η1) Cu2O2-core lie only a few kcal/mol higher and separated by 4-7kcal/mol energy barriers. In all these isomers, the thiol ester is coordinated to the Cu-centers via its two O-ends. Isomers with (SO,OO) and (SO,SO) coordination modes of the thiol esters lie slightly higher and are separated with moderate energy barriers. We found the latter isomers to be vital for the reported CuI-templated cross-coupling of S-acyl thiosalicylamide thiol esters and boronic acids under aerobic conditions. The presence of an anion (halide, carboxylate modeled as formate) in the reaction medium is found to be necessary. Its coordination to the active catalystI1(SO,SO)is the first step of the proposed anion-assisted transmetalation by boronic acid. Overall the transmetalation reaction requires 34.0 kcal/mol and is 24.0 kcal/mol exergonic. This conclusion is in reasonable agreement with available experiments. The C-C bond formation in the transmetalation product requires a 6.3 kcal/mol lower energy barrier and is highly exergonic.
authors.affiliation: Cherry L. Emerson Center for Scientific Computation, Emory University, 30322 Atlanta, Georgia, USA.
authors.forename: Adrián
authors.initials: A
authors.lastname: Varela-Álvarez
authors.forename: Lanny S
authors.initials: LS
authors.lastname: Liebeskind
authors.forename: Djamaladdin G
authors.initials: DG
authors.lastname: Musaev
references.citation: Angew Chem Int Ed Engl. 2008;47(20):3674-6
references.pmid: 18381728
references.citation: J Am Chem Soc. 2006 May 31;128(21):6788-9
references.pmid: 16719449
references.citation: J Chem Phys. 2006 Feb 7;124(5):054107
references.pmid: 16468851
references.citation: Inorg Chem. 2009 Feb 2;48(3):838-45
references.pmid: 19113938
references.citation: J Phys Chem A. 2006 Feb 9;110(5):1991-2004
references.pmid: 16451035
references.citation: Chem Rev. 2004 Feb;104(2):1013-45
references.pmid: 14871148
references.citation: J Am Chem Soc. 2003 May 28;125(21):6394-408
references.pmid: 12785779
references.citation: J Am Chem Soc. 2003 Sep 10;125(36):11027-33
references.pmid: 12952484
references.citation: J Am Chem Soc. 2006 Mar 1;128(8):2654-65
references.pmid: 16492052
references.citation: J Chem Phys. 2008 May 28;128(20):204109
references.pmid: 18513012
references.citation: J Chem Theory Comput. 2008 Jul;4(7):1029-31
references.pmid: 26636355
references.citation: J Am Chem Soc. 2007 Dec 26;129(51):15734-5
references.pmid: 18047333
references.citation: J Chem Theory Comput. 2010 Jul 13;6(7):2040-4
references.pmid: 26615933
references.citation: Phys Rev B Condens Matter. 1988 Jan 15;37(2):785-789
references.pmid: 9944570
references.citation: J Biol Inorg Chem. 2007 Nov;12(8):1221-34
references.pmid: 17710449
references.citation: Angew Chem Int Ed Engl. 2009;48(8):1417-21
references.pmid: 19145620
references.citation: Organometallics. 2009 Jul 22;28(16):4639-4642
references.pmid: 20161122
references.citation: J Am Chem Soc. 2003 Apr 30;125(17):5186-92
references.pmid: 12708870
references.citation: J Chem Theory Comput. 2011 May 10;7(5):1511-23
references.pmid: 26610142
references.citation: Angew Chem Int Ed Engl. 2009;48(13):2276-86
references.pmid: 19067446
references.citation: Angew Chem Int Ed Engl. 2005 Dec 2;44(47):7674-84
references.pmid: 16287179
references.citation: Acc Chem Res. 2007 Jul;40(7):601-8
references.pmid: 17458929
references.citation: Angew Chem Int Ed Engl. 2003 Dec 15;42(48):5961-5
references.pmid: 14679543
references.citation: J Am Chem Soc. 2009 Jul 8;131(26):9258-67
references.pmid: 19530656
references.citation: J Am Chem Soc. 2009 Jul 15;131(27):9547-61
references.pmid: 19537806
references.citation: J Chem Theory Comput. 2009 Apr 14;5(4):808-21
references.pmid: 26609587
references.citation: Phys Rev A Gen Phys. 1988 Sep 15;38(6):3098-3100
references.pmid: 9900728
references.citation: J Phys Chem A. 2010 Dec 30;114(51):13442-4
references.pmid: 21133342
references.citation: Inorg Chem. 2007 Apr 16;46(8):3322-35
references.pmid: 17371011
references.citation: Chem Rev. 2005 Aug;105(8):2999-3093
references.pmid: 16092826
references.citation: J Am Chem Soc. 2009 Mar 11;131(9):3230-45
references.pmid: 19216527