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. Author manuscript; available in PMC: 2018 Jun 1.
Published in final edited form as: Nat Chem. 2017 Jul 17;9(12):1269–1275. doi: 10.1038/nchem.2816

Table 1.

Probing efficiency and diastereoselectivity with different (achiral) catalyst types.

graphic file with name nihms892143u2.jpg
Entry Ligand Conv. (%)* Yield (%)† d.r.*
1 PPh3 60 49 >98:2
2 PCy3 71 52 >98:2
3 rac-binap 75 72 >98:2
4 4a 80 66 >98:2
5 4b 55 53 >98:2
6 4c >98 90 >98:2

Reactions were carried out under N2 atmosphere; 1.2:1 ratio of ketimine:allene was used.

*

Conversion (based on allene consumption; (includes desired and decomposition products) and diastereomeric ratio (d.r.) values were measured by analysis of 400 MHz 1H NMR spectra of unpurified mixtures; variance of values is estimated to be <±2%.

†

Yield of isolated and purified product (<±5%). See the Supplementary Information for details).

Abbreviations: TBS, tert-butyldimethylsilyl; pin, pinacolato; Mes, 2,4,6-Me3C6H2; Cy, cyclohexyl; rac, racemic; binap, 2,2’-bis(diphenylphosphino)-1,1’-binaphthalene.