An Accidental Synthetic Chemist

Dedicated to Professor Paul Knochel on the occasion of his 70th birthday.

Abstract

A journey is described that began as a genetics major, passed through a brief period as a formal synthetic organic chemist, and proceeded through a decades-long quest to be a physical organic–organometallic chemist. Although a preponderance of our program has emphasized elucidating fundamental principles of how aggregation and solvation influence reactivity, this review focuses on the results that have implications in organic synthesis.

1. Introduction

2. The Early Years

3. Lithium Amides and N-Lithiated Species

4. Sodium Amides

5. Potassium Hexamethyldisilazide and Related Potassium Alkyl(trimethylsilyl) Amides

6. Carbanions

7. Enolates

8. Conclusions

Keywords

aggregation - asymmetric synthesis - carbanions - enantioselectivity - lithiation - solvent effects - stereoselective synthesis - organometallic reagents

Publikationsverlauf

Eingereicht: 28. Februar 2025

Angenommen nach Revision: 26. März 2025

Artikel online veröffentlicht:
25. Juli 2025

• References

• 1 Collum DB, Ganem B, Chen SC. J Org Chem. 1978; 43: 4393
• 2 From Wikipedia. ‘Murderers’ Row were the baseball teams of the New York Yankees in the late 1920s, widely considered some of the best teams in history.’ https://en.wikipedia.org/wiki/Murderers%27_Row (accessed April 22, 2025)
• 3a Still WC. J Am Chem Soc. 1977; 99: 4836
• 3b Still WC. J Am Chem Soc. 1978; 100: 1481
• 3c Still WC, Mitra A. Tetrahedron Lett. 1978; 33: 2659
• 4 Still WC, Kahn M, Mitra A. J Org Chem. 1978; 43: 2923
• 5 Still WC. J Am Chem Soc. 1977; 99: 4186
• 6a Still WC, Macdonald TL. Tetrahedron Lett. 1976; 31: 2659
• 6b Macdonald TL, Still WC. J Am Chem Soc. 1975; 97: 5280
• 6c For the first hint of higher order cuprates, see: House HO, Koepsell DG, Campbell WJ. J Org Chem. 1972; 37: 1003
• 7 Still WC. J Am Chem Soc. 1979; 101: 2493
• 8 Still WC, McDonald III JH, Collum DB, Mitra A. Tetrahedron Lett. 1979; 33: 593
• 9 Still WC, Tsai M-Y. J Am Chem Soc. 1980; 102: 3654
• 10a Collum DB, McDonald III. JH, Still WC. J Am Chem Soc. 1980; 102: 2117
• 10b Collum DB, McDonald III. JH, Still WC. J Am Chem Soc. 1980; 102: 2118
• 10c Collum DB, McDonald III. JH, Still WC. J Am Chem Soc. 1980; 102: 2120
• 11 Corey EJ, Nicolaou KC, Melvin LS. J Am Chem Soc. 1975; 97: 653
• 12 Fukuyama T, Wang CLJ, Kishi Y. J Am Chem Soc. 1979; 101: 260
• 13 Mohamadi F, Hallock JH, Collum DB. J Am Chem Soc. 1983; 105: 6882
• 14 Suzuki K, Shoji S, Kobayashi E, Inomata K. Tetrahedron: Asymmetry. 2001; 12: 2789 and references cited therein
• 15 Kubo I, Pettei MJ, Hirotsu K, Tsuji H, Kubota T. J Am Chem Soc. 1978; 100: 628
• 16 Kahne D, Collum DB. Tetrahedron Lett. 1981; 22: 5011
• 17 Corey EJ, Enders D. Chem Ber. 1978; 111: 1337
• 18a Kahne D, Gut S, DePue R. et al. J Am Chem Soc. 1984; 106: 4865
• 18b Wanat RA, Collum DB. J Am Chem Soc. 1985; 107: 2078
• 19 Mohamadi F, Collum DB. Tetrahedron Lett. 1984; 25: 271
• 20a Snider BB, Hui RAHF. J Org Chem. 1985; 50: 5167
• 20b Snider BB, Hui RAHF, Kulkarni YS. J Am Chem Soc. 1985; 107: 2194
• 21a McGuirk PR, Collum DB. J Am Chem Soc. 1982; 104: 4496
• 21b McGuirk PR, Collum DB. J Org Chem. 1984; 49: 843
• 22a Yeung BWA, Contelles JLM, Fraser-Reid B. Chem Commun. 1989; 1160
• 22b Smith AB, Empfield JR. Chem Pharm Bull. 1999; 47: 1671 and references cited therein
• 23 Wanat RA, Collum DB. Organometallics. 1985; 5: 120
• 24a Werner H, Mahr N, Frenking G, Jonas V. Organometallics. 1995; 14: 619
• 24b Martín C, Molina F, Alvarez E, Belderrain TR. Chem – Eur J. 2011; 17: 14885
• 24c Ewies EF, El-Sayed NF, Boulos LS. J Chem Res. 2016; 40: 417
• 25 Popik VV. Ethyl diazoacetate. In Paquette LA. ed e-EROS Encyclopedia of Reagents for Organic Synthesis. Vol 1. Chichester: John Wiley & Sons; 2011
• 26 Hallock JS, Galiano-Roth AS, Collum DB. Organometallics. 1988; 7: 2486
• 27 Smith JM, Dixon JA, deGruyter JN, Baran PS. J Med Chem. 2019; 62: 2256
• 28 For a substitution at phosphorus of a coordinated halophosphine followed by orthometalation, see: Bedford RB, Betham M. et al. Chem Commun. 2008; 990
• 29a For reviews of alcoholyses of coordinated halophospines, see Roundhill DM, Sperline RP, Beaulieu WP. Coord Chem Rev. 1978; 26: 263
• 29b Kraihanzel CS. J Organomet Chem. 1974; 73: 137
• 30 Feldman J, Collum DB. Unpublished results
• 31a DePue RT, Ziller JW, Churchill MR, Collum DB. J Am Chem Soc. 1985; 107: 2131
• 31b DePue RT, Klang JA, Collum DB. Organometallics. 1986; 5: 1015
• 32 Lemper AL, Tieckelmann H. Tetrahedron Lett. 1964; 5: 3053
• 33 Klang JA, Collum DB. Organometallics. 1988; 7: 1532
• 34 DePue JS. Ph.D. Dissertation. USA: Cornell University; 1990
• 35 Rai R, Aubrecht KB, Collum DB. Tetrahedron Lett. 1995; 36: 3111
• 36a Lansbury PT, DuBois GE. Tetrahedron Lett. 1972; 13: 3305
• 36b Huff BJL, Tuller FN, Caine D. J Org Chem. 1969; 34: 3070
• 36c House HO, Umen MJ. J Org Chem. 1973; 38: 1000
• 36d Howe R, McQuillin FJ. J Chem Soc. 1958; 1194
• 36e Kuwajima I, Nakamura E. J Am Chem Soc. 1975; 97: 3257
• 36f Djerassi. Osiecki J, Eisenbraun EJ. J Am Chem Soc. 1961; 83: 4433
• 36g House HO, Tefertiller BA, Olmstead HD. J Org Chem. 1968; 33: 935
• 36h Kuehne ME. J Org Chem. 1970; 35: 171
• 36i Kuwajima I, Nakamura E, Shimizu M. J Am Chem Soc. 1982; 104: 1025
• 37 Fraser RR. Comprehensive Carbanion Chemistry. New York: Elsevier; 1980
• 38a Szwarc M. ed Ions and Ion Pairs in Organic Reactions. Vols 1. and 2 New York: John Wiley & Sons; 1972
• 38b Wakefield BJ. The Chemistry of Organolithium Compounds. New York: Pergamon Press; 1974
• 38c Brown TL. Pure Appl Chem. 1970; 23: 447
• 39a Williard PG, Salvino JM. J Org Chem. 1993; 58: 1
• 39b Barnett NDR, Mulvey RE, Clegg W, O’Neil PA. J Am Chem Soc. 1991; 113: 8187
• 39c Mulvey RE, Robertson SD. Angew Chem Int Ed. 2013; 52: 11470
• 40 Collum DB, McNeil AJ, Ramírez A. Angew Chem Int Ed. 2007; 46: 3002
• 41 Collum DB. Acc Chem Res. 1992; 25: 448
• 42 Reich HJ. Chem Rev. 2013; 113: 7130
• 43 Gupta L, Hoepker AC, Singh KJ, Collum DB. J Org Chem. 2009; 74: 2231
• 44 Algera RF, Gupta L, Hoepker AC. et al. J Org Chem. 2017; 82: 4513
• 45 Barr D, Snaith R, Wright DS, Mulvey RE, Wade K. J Am Chem Soc. 1987; 109: 7891
• 46a Seebach D. Proceedings of the Robert A. Welch Foundation Conferences on Chemistry and Biochemistry. New York: John Wiley & Sons; 1984: 93
• 46b Seebach D. Chem A Int Ed Engl. 1988; 27: 1624
• 46c See also Harrison-Marchand A, Mongin F. Chem Rev. 2013; 113: 7470
• 47a Galiano-Roth AS, Kim Y-J, Gilchrist JH, Harrison AT, Fuller DJ, Collum DB. J Am Chem Soc. 1991; 113: 5053
• 47b Hall PL, Gilchrist JH, Collum DB. J Am Chem Soc. 1991; 113: 9571
• 47c Hall PL, Gilchrist JH, Harrison AT, Fuller DJ, Collum DB. J Am Chem Soc. 1991; 113: 9575
• 48 Evans DA, Scheidt KA, Johnston JN, Willis MC. J Am Chem Soc. 2001; 123: 4480
• 49 Lucht BL, Collum DB. Acc Chem Res. 1999; 32: 1035
• 50 Zhao P, Collum DB. J Am Chem Soc. 2003; 125: 14411
• 51 Godenschwager P, Collum DB. J Am Chem Soc. 2008; 130: 8726
• 52a Li BX, Le DN, Mack KA. et al. J Am Chem Soc. 2017; 139: 10777
• 52b Mack KA, McClory A, Zhang H, Gosselin F, Collum DB. J Am Chem Soc. 2017; 139: 12182
• 53a Chaubet G, Goh SS, Mohammad M. et al. Chem – Eur J. 2017; 23: 14080
• 53b Graczyk PP, Zbrojkiewicz O, Nerdinger S. Tetrahedron: Asymmetry. 2017; 28: 387
• 53c Goh SS, Chaubet G, Gockel B. et al. Angew Chem Int Ed. 2015; 54: 12618
• 53d Hiersemann M, Jaschinski T. Selected diastereoselective reactions. Diastereoface-differentiating Claisen, cope, and [2,3]-Wittig rearrangements in contemporary natural product synthesis. In Carreira EM, Yamamoto H. eds Comprehensive Chirality. Vol 2. Amsterdam: Elsevier; 2012: 625
• 53e Loke I, Bentzinger G, Holz J. et al. Org Biomol Chem. 2016; 14: 884
• 53f Harker WRR, Carswell EL, Carbery DR. Org Biomol Chem. 2012; 10: 1406
• 53g Majumdar KC, Nandi RK. Tetrahedron. 2013; 69: 6921
• 54 Snaddon TN, Buchgraber P, Schulthoff S, Wirtz C, Mynott R, Fürstner A. Chem Eur J. 2010; 16: 12133
• 55 Claisen rearrangements of alkali metal enolates have been reported on a number of occasions, see: Hiersemann M, Nubbemeyer U. eds The Claisen Rearrangement: Methods and Applications. Chapter 5 Weinheim: Wiley-VCH; 2007
• 56a Seyferth D. Organometallics. 2006; 25: 2
• 56b Seyferth D. Organometallics. 2009; 28: 2
• 56c Lochmann L, Janata M. Eur J Chem. 2014; 12: 537
• 56d Robertson SD, Uzelac M, Mulvey RE. Chem Rev. 2019; 119: 8332
• 56e Armstrong DR, Kennedy AR, Mulvey RE, Robertson SD. Chem – Eur J. 2011; 17: 8820
• 56f Mordini A. Sodium and potassium. In Mingos DMP, Crabtree RH. eds Comprehensive Organometallic Chemistry III. Vol 9. Amsterdam: Elsevier; 2007: 3
• 56g Benkeser RA, Foster DJ, Sauve DM, Nobis JF. Chem Rev. 1957; 57: 867
• 56h Sreedharan R, Gandhi T. Chem – Eur J. 2024; 30: e202400435
• 57 Ma Y, Algera RF, Collum DB. J Org Chem. 2016; 81: 11312
• 58 Woltornist RA, Ma Y, Algera RF, Zhou Y, Zhang Z, Collum DB. Synthesis. 2020; 52: 1478
• 59a For recent studies illustrating the synthetic potential of organosodium chemistry, see Gentner TX, Mulvey RE. Angew Chem Int Ed. 2021; 60: 9247
• 59b Anderson DE, Tortajada A, Hevia E. Angew Chem Int Ed. 2023; 62: e202218498
• 59c Harenberg JH, Reddy R, Reddy A, Karaghiosoff K, Knochel P. Angew Chem Int Ed. 2022; 61: e202203807
• 59d Davison N, McMullin CL, Zhang L. et al. J Am Chem Soc. 2023; 145: 6562
• 59e De PB, Asako S, Ilies L. Synthesis. 2021; 53: 3180
• 59f Fuentes MA, Zabala A, Kennedy AR, Mulvey RE. Chem – Eur J. 2016; 22: 14968
• 59g Asako S, Takahashi I, Nakajima H, Ilies L, Takai K. Commun Chem. 2021; 4: 76
• 59h Harenberg JH, Weidmann N, Wiegand AJ, Hoefer CA, Annapureddy RR, Knochel P. Angew Chem Int Ed. 2021; 60: 14296
• 59i Wong HNC. Nat Catal. 2019; 2: 282
• 59j Asako S, Nakajima H, Takai K. Nat Catal. 2019; 2: 297
• 59k Klett J. Chem Eur J. 2021; 27: 888
• 59l Anderson DE, Tortajada A, Hevia E. Angew Chem Int Ed. 2024; 63: e202313556
• 59m Asako S, Kodera M, Nakajima H, Takai K. Adv Synth Catal. 2019; 361: 3120
• 59n Dilauro G, Luccarelli C, Quivelli AF, Vitale P, Perna FM, Capriati V. Angew Chem Int Ed. 2023; 62: e202304720
• 59o Tortajada A, Hevia E. J Am Chem Soc. 2022; 144: 20237
• 59p Ong DY, Pang JH, Chiba S, Synth J. Org Chem Jpn. 2019; 77: 1060
• 60 Algera RF, Ma Y, Collum DB. J Am Chem Soc. 2017; 139: 7921
• 61 Liotta CL, Berkner J, Wright J, Fair B. Mechanisms and applications of solid–liquid phase-transfer catalysis. In Halpern M. ed Phase-Transfer Catalysis. ACS Symposium Series 659. Chap. 3. Washington DC: American Chemical Society; 1997
• 62a Woltornist RA, Collum DB. J Am Chem Soc. 2020; 142: 6852
• 62b Woltornist RA, Collum DB. J Org Chem. 2021; 86: 2406
• 63 Woltornist RA, Collum DB. J Am Chem Soc. 2021; 143: 17452
• 64 You Q, Collum DB. J Am Chem Soc. 2023; 145: 23568
• 65a Ma Y, Lui NM, Keresztes J, Woltornist RA, Collum DB. J Org Chem. 2022; 87: 14223
• 65b You Q, Ma Y, Woltornist RA. et al. J Am Chem Soc. 2024; 145: 30397
• 66 Spivey JA, Collum DB. J Am Chem Soc. 2024; 145: 17827
• 67 Spivey JA, Collum DB. Organometallics. 2024; 32: 684
• 68 Eis MJ, Wrobel JE, Ganem B. J Am Chem Soc. 1984; 106: 3693
• 69 Aubrecht KB, Winemiller MD, Collum DB. J Am Chem Soc. 2000; 122: 11084
• 70 Ma Y, Lobkovsky E, Collum DB. J Org Chem. 2005; 70: 2335
• 71a Thompson AS, Corley EG, Huntington MF, Grabowski EJJ. Tetrahedron Lett. 1995; 36: 8937
• 71b Grabowski EJJ. Reflections on process research. In Abdel-Magid AF, Ragan JA. eds Chemical Process Research: The Art of Practical Organic Synthesis. Washington DC: American Chemical Society; 2004: 1-21
• 72a Thompson A, Corley EG, Huntington MF, Grabowski EJJ, Remenar JF, Collum DB. J Am Chem Soc. 1998; 120: 2028
• 72b Xu F, Reamer RA, Tillyer R. et al. J Am Chem Soc. 2000; 122: 11212
• 73 Kauffman GS, Harris GD, Dorow RL. et al. Org Lett. 2000; 2: 3119
• 74a Parsons Jr RL, Fortunak JM, Dorow RL. et al. J Am Chem Soc. 2001; 123: 9135
• 74b Briggs TF, Winemiller MD, Collum DB. et al. J Am Chem Soc. 2004; 126: 5427
• 74c Briggs TF, Winemiller MD, Xiang B, Collum DB. J Org Chem. 2001; 66: 6291
• 75 Parsons Jr RL. Opin Drug Discovery Dev. 2000; 3: 783
• 76 Coe JW, Wirtz MC, Bashore CG, Candler J. Org Lett. 2004; 6: 1589
• 77a Ramírez A, Candler J, Bashore CG, Wirtz MC, Coe JW, Collum DB. J Am Chem Soc. 2004; 126: 14700
• 77b Riggs JC, Ramírez A, Cremeens ME. et al. J Am Chem Soc. 2008; 130: 3406
• 78 Thompson CM. Dianion Chemistry in Organic Synthesis. Boca Raton: CRC Press; 1994
• 79 Han Y, Ma Y, Keresztes I, Collum DB, Corey EJ. Org Lett. 2014; 16: 4678
• 80 Ma Y, Breslin S, Keresztes I, Lobkovsky E, Collum DB. J Org Chem. 2008; 73: 9610
• 81a Davis ML, Wakefield BJ, Wardell JA. Tetrahedron. 1992; 48: 939
• 81b Juchum M, Guenther M, Doering E, Sievers-Engler A, Laemmerhofer M, Laufer S. J Med Chem. 2017; 60: 4636
• 82 Base-mediated functionalizations of 3-picoline are not common and are restricted to narrow groups of electrophiles that include alkyl halides and unreactive carbonyl groups, presumably owing to the dimerization
• 83 For a discussion and examples of base-mediated self-condensation of heterocycles, see ref. 80
• 84a For mixed condensation of heteroaryllithiums with heteroarenes, see Gros P, Fort Y. J Chem Soc Perkin Trans. 1998; 1: 3515
• 84b Kauffmann T. Angew Chem Int Ed Engl. 1979; 18: 1 and references cited therein
• 85 Ma Y, Collum DB. Unpublished results
• 86a Comins DL, Higuchi K, Young DW. Advances in Heterocyclic Chemistry. 2013; 110: 175
• 86b Comparini L. M, Pineschi M. Molecules; 2023 28:6186
• 87 West SP, Bisai A, Lim AD, Narayan RR, Sarpong R. J Am Chem Soc. 2009; 131: 11187
• 88 Gruver JM, West SP, Collum DB, Sarpong R. J Am Chem Soc. 2010; 132: 13212
• 89 Gladfelder J, Ghosh S, Podunavac M. et al. J Am Chem Soc. 2019; 141: 15024
• 90 Much of the stereochemical analysis remains unpublished
• 91 Czekaj M, Klein SI, Guertin KR. et al. Bioorg Med Chem Lett. 2002; 12: 1667
• 92a For instances in which heteroaggregation offered insights into homoaggregation, see Kissling RM, Gagne MR. J Org Chem. 2001; 66: 9005
• 92b Galiano-Roth AS, Michaelides EM, Collum DB. J Am Chem Soc. 1988; 110: 2658
• 92c Reich HJ, Goldenberg WS, Gudmundsson BÖ. et al. J Am Chem Soc. 2001; 123: 8067
• 92d Gilchrist JH, Harrison AT, Fuller DJ, Collum DB. J Am Chem Soc. 1990; 112: 4069
• 92e Hoffmann D, Collum DB. J Am Chem Soc. 1998; 120: 5810
• 92f Fraenkel G, Henrichs M, Hewitt M, Su BM. J Am Chem Soc. 1984; 106: 255
• 92g Novak DP, Brown TL. J Am Chem Soc. 1972; 94: 3793
• 92h Desjardins S, Flinois K, Oulyadi H. et al. Organometallics. 2003; 22: 4090
• 92i Günther H, In Gielen M, Willem R, Wrackmeyer B. eds Advanced Applications of NMR to Organometallic Chemistry. New York: Wiley & Sons; 1996: 247-290
• 92j Weingarten H, Van Wazer JR. J Am Chem Soc. 1965; 87: 724
• 92k Góralski P, Legoff D, Chabanel M. J Organomet Chem. 1993; 456: 1
• 93 McNeil AJ, Toombes GES, Chandramouli SV. et al. J Am Chem Soc. 2004; 126: 5938
• 94 Renny JS, Tomasevich LL, Tallmadge EH, Collum DB. Angew Chem Int Ed. 2013; 52: 11998
• 95 For examples of and leading references to various examples of enolate–solvent combinations studied by MCV, see refs 52, 94, 99, 103, 108 and 119
• 96 Casy BM, Flowers RA. J Am Chem Soc. 2011; 133: 11492
• 97 McNeil AJ, Toombes GES, Gruner SM. et al. J Am Chem Soc. 2004; 126: 16559
• 98 Wright S. W, Choi C, Chung S. et al. Org Lett. 2015; 17: 5204
• 99a Houghton MJ, Biok NA, Huck CJ. et al. J Org Chem. 2016; 81: 4149
• 99b Houghton MJ, Huck CJ, Wright SW, Collum DB. J Am Chem Soc. 2016; 116: 10276
• 100 Huck C. J, Houghton M. J, Collum D. B. Unpublished results
• 101 Singer RA, Ragan JA, Bowles P. et al. Org Process Res Dev. 2014; 18: 26
• 102 Reyes-Rodríguez GJ, Algera RF, Collum DB. J Am Chem Soc. 2017; 139: 1233
• 103 Tallmadge EH, Collum DB. J Am Chem Soc. 2015; 137: 13087
• 104 Tallmadge EH, Jermaks J, Collum DB. J Am Chem Soc. 2016; 138: 345
• 105 March J. Advanced Organic Chemistry. 4th ed New York: John Wiley& Sons; 1980: 959
• 106a Ager DJ, Prakash I, Schaad DR. Chem Rev. 1996; 96: 835
• 106b Wu G, Huang M. Chem Rev. 2006; 106: 2596
• 106c Farina V, Reeves JT, Senanayake CH, Song JJ. Chem Rev. 2006; 106: 2734
• 106d G.-Q L, Y-M. Chan ASC. Principles and Applications of Asymmetric Synthesis. New York: John Wiley & Sons; 2001: 135
• 106e Palomo C, Oiarbide M, Garcia JM. Chem Soc Rev. 2004; 33: 65
• 106f Baiget J, Cosp A, Galvez E, Gomez-Pinal L, Romea P, Urpi F. Tetrahedron. 2008; 64: 5637
• 106g Mahrwald R. ed Modern Aldol Reactions. Vols 1. and 2 Wiley-VCH; 2004
• 107 Jermaks J, Tallmadge EH, Keresztes K, Collum DB. J Am Chem Soc. 2018; 140: 3077
• 108 Zhang Z, Collum DB. J Am Chem Soc. 2019; 141: 388
• 109 Li B-J, El-Nachef C, Beauchemin AM. Chem Commun. 2017; 53: 13192
• 110a Koskinen AMP, Kataja AO. Org React. 2015; 86: 105
• 110b Mahrwald R. In Mahrwald R. ed Modern Aldol Reactions. Vol 2. Weinheim: Wiley-VCH; 2004: 327
• 111 Price KE, Broadwater SJ, Walker BJ, McQuade DT. J Org Chem. 2005; 70: 3980
• 112a Evans DA, Kim AS, Skrydstrup T, Taaning RH. (S)-4-Benzyl-2-oxazolidinone. In E-EROS Encyclopedia of Reagents for Organic Synthesis. New York: John Wiley & Sons; 2007: 1-18.6
• 112b Evans DA, Adams DJ, Kwan EE. J Am Chem Soc. 2012; 134: 8162
• 112c Cowden CJ, Paterson I. Org React. 1997; 51: 1
• 113 Zhang Z, Collum DB. J Org Chem. 2017; 82: 7595
• 114a Tomooka K, Komine N, Nakai T. Chirality. 2000; 12: 505
• 114b Nakai T, Mikami K. Org React. 1994; 46: 105
• 114c The Wittig rearrangement. In Knochel P. Molander GA. eds Comprehensive Organic Synthesis. 2nd ed Vol 3. Amsterdam: Elsevier; 2014: 1038
• 115 Zhang Z, Collum DB. J Org Chem. 2019; 84: 10892
• 116 Myers AG, Yang BH, Chen H, McKinstry L, Kopecky DJ, Gleason JL. J Am Chem Soc. 1997; 119: 6496
• 117 Zhou Y, Jermaks J, Keresztes I, MacMillan SN, Collum DB. J Am Chem Soc. 2019; 141: 5444
• 118 Zhou Y, Keresztes I, MacMillan SN, Collum DB. J Am Chem Soc. 2019; 141: 16865
• 119 Yamashita Y, Emura Y, Odashima K, Koga K. Tetrahedron Lett. 2000; 41: 209
• 120 Frizzle J, Nani RR, Martinelli MJ, Moniz GA. Tetrahedron Lett. 2011; 52: 5653
• 121 Stivala CE, Zakarian A. J Am Chem Soc. 2011; 133: 11936
• 122 Ma Y, Stivala CE, Wright AM. et al. J Am Chem Soc. 2013; 135: 16853
• 123 Ma Y, Mack KA, Liang J, Keresztes I, Collum DB, Zakarian A. Angew Chem Int Ed. 2016; 55: 10097
• 124 Lu P, Jackson J, Yu K. et al. J Am Chem Soc. 2017; 139: 537
• 125a Oppolzer W. Tetrahedron. 1987; 43: 1969
• 125b Heravi MM, Zadsirjan V. Tetrahedron: Asymmetry. 2014; 25: 1061
• 126a Lui NM, MacMillan SN, Collum DB. J Am Chem Soc. 2022; 144: 23379
• 126b Lui NM, Collum DB. Org Chem Front. 2023; 10: 4750