Diastereoselective lithiation of n-silyl-protected (S)-tetrahydro-1H- pyrrolo[1,2-c]imidazol-3(2H)-one

Article abstract of DOI:10.3987/COM-13-S(S)29

An L-proline-derived imidazolone protected with an N-triethylsilyl (N-TES) group undergoes diastereoselective lithiation-electrophile quench to give C5-substituted products with syn stereochemistry. Unlike the previous N-t-Bu analogues, the N-TES derivatives may be easily N-desilylated to give secondary ureas that serve as precursors to N-phenyl chiral bicyclic guanidines.

Full text of DOI:10.3987/COM-13-S(S)29

Supporting Information for
DIASTEREOSELECTIVE LITHIATION OF N-SILYL-PROTECTED
(S)-TETRAHYDRO-1H-PYRROLO[1,2-c]IMIDAZOL-3(2H)-ONE
Costa Metallinos*, Seyed Iraj Sadraei, and Nadezda Zhukovskaya
Department of Chemistry, Brock University, 500 Glenridge Avenue, St. Catharines,
Ontario L2S 3A1, Canada

NH
N
O
9
300 MHz, CDCl3

N
N
TES
Me
O
16b
300 MHz, CDCl3

N TES
N
O
16e
300 MHz, CDCl3

N TES
N
TMS
O
16a
150 MHz, CDCl3

N TES
N
Bu3Sn
O
16d
300 MHz, CDCl3
N TES
N
Bu3Sn
O
16d
75 MHz, CDCl3

N TES
N
HO
Ph
O
Ph
16c
300 MHz, CDCl3
N TES
N
HO
Ph
O
Ph
16c
75 MHz, CDCl3

NH
N
Me
O
17b
300 MHz, CDCl3
NH
N
Me
O
17b
150 MHz. CDCl3

NH
N
O
17e
300 MHz, CDCl3
NH
N
O
17e
75 MHz, CDCl3

NH
N
Bu3Sn
O
17d
300 MHz, CDCl3

NH
N
HO
Ph
O
Ph
17c
300 MHz, CDCl3

TMS
N
N
O
10
300 MHz, CDCl3

Me
TMS
TMS
N Si
Me
N
O
12
300 MHz, CDCl3
Me
TMS
TMS
N Si
Me
N
O
12
150 MHz, CDCl3

N
N
Ph
Me
O
18b
75 MHz, CDCl3

N
N
Ph
TMS
O
18a
75 MHz, CDCl3

N
N
Ph
Me
NH
19b
300 MHz, CDCl3
N
N
Ph
Me
NH
19b
75 MHz, CDCl3

N
N
Ph
TMS
NH
19a
300 MHz, CDCl3
N
N
Ph
TMS
NH
19a
75 MHz, CDCl3

N
N
TES
Me
O
16b

N TES
N
Bu3Sn
O
16d
75.4 MHz, CDCl3

Me
TMS
TMS
N Si
Me
N
O
12