Hydroalkylation of alkynyl Ethers via a gold(I)-catalyzed 1,5-hydride shift/cyclization sequence

Article abstract of DOI:10.1021/ja9100134

A series of alkynyl ethers react with an electrophilic gold(I) catalyst to produce a range of structurally complex spiro or fused dihydrofurans and dihydropyrans via a 1,5-hydride shift/cyclization sequence. This hydroalkylation process, which is performed under practical experimental conditions, can be applied to terminal as well as ester-substituted alkynes. It allows the efficient conversion of secondary or tertiary sp³ C-H bonds into new C-C bonds by the nucleophilic addition of a vinylgold species onto an oxonium intermediate. The stereoselectivity of the cycloisomerization process toward the formation of a new five- or six-membered cycle appears to be dependent on steric factors and the alkyne substitution pattern.

Full text of DOI:10.1021/ja9100134

Hydroalkylation of Alkynyl ethers via a Gold(I)-Catalyzed 1,5-Hydride Shift / Cyclization Sequence
Igor Dias Jurberg, Yann Odabachian, and Fabien Gagosz*
Laboratoire de Synthèse Organique, UMR 7652 CNRS / Ecole Polytechnique, 91128 Palaiseau, France.
Supporting Information
1H- and 13C-NMR Spectra of starting materials 1a-l, 7a-e, 10d-f, 12, 16 and 31
S-1

1a
O
CO Me
2
CO Me
2
8
.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
ppm (f1)
S-2

1a
O
CO Me
2
CO Me
2
2
00
150
100
50
0
ppm (f1)
05(1a)
4
S-3

D
O
1
2
CO Me
2
CO Me
2
8
.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
ppm (f1)
S-4

D
O
1
2
CO Me
2
CO Me
2
2
00
150
100
50
0
ppm (f1)
S-5

CO Me
O
2
D
16
CO Me
2
8
.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
ppm (f1)
S-6

CO Me
O
2
D
16
CO Me
2
2
00
150
100
50
0
ppm (f1)
S-7

O
1b
OAc
AcO
8
.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
ppm (f1)
S-8

O
1b
OAc
AcO
2
00
150
100
50
0
ppm (f1)
S-9

1
c
O
CO Me
2
CO Me
2
8
.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
ppm (f1)
S-10

1
c
O
CO Me
2
CO Me
2
2
00
150
100
50
0
ppm (f1)
2
00
150
100
50
0
ppm (f1)
S-11

1d
O
CO Me
2
CO Me
2
8
.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
ppm (f1)
S-12

1d
O
CO Me
2
CO Me
2
2
00
150
100
50
0
ppm (f1)
2
00
150
100
50
0
ppm (f1)
S-13

MeO C
2
1e
O
CO Me
2
CO Me
2
8
.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
ppm (f1)
S-14

MeO C
2
1e
O
CO Me
2
CO Me
2
2
00
150
100
50
0
ppm (f1)
2
00
150
100
50
0
ppm (f1)
S-15

-
H
1
f
O
H
CO Me
2
CO Me
2
8
.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
ppm (f1)
S-16

H
1
f
O
H
CO Me
2
CO Me
2
2
00
150
100
50
0
ppm (f1)
2
00
150
100
50
0
ppm (f1)
S-17

O
EtO C
CO Me
1g
2
2
CO Me
2
8
.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
ppm (f1)
S-18

O
EtO C
CO Me
1g
2
2
CO Me
2
2
00
150
100
50
0
ppm (f1)
2
00
150
100
50
0
ppm (f1)
S-19

O
1h
EtO C
CO Me
2
2
CO Me
2
8
.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
ppm (f1)
S-20

2
00
150
100
50
0
ppm (f1)
O
1h
EtO C
CO Me
2
2
CO Me
2
2
00
150
100
50
0
ppm (f1)
S-21

O
O
1
i
CO Me
2
CO Me
2
8
.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
ppm (f1)
S-22

2
00
150
O
100
50
0
ppm (f1)
O
1
i
CO Me
2
CO Me
2
2
00
150
100
50
0
ppm (f1)
S-23

O
O
1j
EtO C
CO Me
2
2
CO Me
2
8
.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
ppm (f1)
S-24

O
O
1j
EtO C
CO Me
2
2
CO Me
2
2
00
150
100
50
0
ppm (f1)
2
00
150
100
50
0
ppm (f1)
S-25

CO Me
O
2
1
k
Br
CO Me
2
8
.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
ppm (f1)
S-26

CO Me
O
2
1
k
Br
CO Me
2
2
00
150
100
50
0
ppm (f1)
S-27

O
CO Me
2
Ph
CO Me
2
1
l
8
.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
ppm (f1)
S-28

O
CO Me
2
Ph
CO Me
2
1
l
2
00
150
100
50
0
ppm (f1)
S-29

MeO C CO Me
2
2
7a
O
8
.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
ppm (f1)
S-30