Organoactinide-, organolanthanide-, and organogroup-4-mediated hydrothiolation of terminal alkynes with aliphatic, aromatic and benzylic thiols
An efficient and highly Markovnikov selective organoactinide-, organolanthanide-, and organozirconium-catalyzed addition of aryl, benzyl, and aliphatic thiols to terminal alkynes is described. The corresponding vinyl sulfides are produced with little or no side-products.
1. A method of preparing a vinyl sulfide comprising treating a terminal alkyne with an aliphatic, benzylic or aromatic thiol in the presence of a catalyst selected from the group consisting of an organolanthanide-, organoactinide- and organoGroup-4-complex.
2. A method according to claim 1 wherein the vinyl sulfide is prepared with >90% Markovnikov selectivity.
3. A method according to claim 2 wherein the vinyl sulfide is prepared with no or substantially no double-thiolated side product.
4. A method according to claim 3 wherein the vinyl sulfide is prepared through an alkyne insertion pathway followed by a thiol-mediated protonolysis.
5. A method according to claim 4 wherein the alkyne insertion pathway is turnover-limiting.
6. A method according to claim 1 wherein the catalyst is selected from the group consisting of:
CGCM 1 R 1 2 , wherein M 1 is selected from an actinide metal and Zr(IV), and R 1 is selected from NMe 2 , NEt 2 and Me;
CGCM 2 R 2 , wherein M 2 is lanthanide metal and R 2 is N(TMS) 2 ;
Cp* 2 M 1 R 3 2 , wherein R 3 is selected from NMe 2 , NEt 2 , Me and CH 2 TMS;
Cp* 2 M 2 R 4 , wherein R 4 is selected from N(TMS) 2 and CH(TMS) 2 ;
Me 2 SiCp″ 2 M 3 R 5 2 , wherein M 3 is an actinide metal, and R 5 is selected from CH 2 TMS and Bn;
M 2 [R 4 ] 3 ,
Cp*M 4 R 6 , wherein M 4 is a Group 4 metal and R 6 is selected from Bn 3 and Cl 2 NMe 2 ; and
M 3 (R 3 ) 4 .
7. A method according to claim 6 wherein the catalyst is selected from Cp* 2 SmN(TMS) 2 , Me 2 SiCp″ 2 Th[CH 2 (TMS)] 2 , CGCZrMe 2 , Cp* 2 YCH(TMS) 2 , Cp* 2 YN(TMS) 2 , Me 2 SiCp″ 2 UBn 2 , Cp* 2 ZrMe 2 , CGCSmN(TMS) 2 , CGCU(NMe 2 ) 2 , Cp*ZrBn 3 , La[N(TMS) 2 ] 3 , CGCTh(NMe 2 ) 2 , Zr[NMe 2 ] 4 , Nd[N(TMS) 2 ] 3 , U(NEt 2 ) 4 , Cp*ZrCl 2 NMe 2 , Lu[CH(TMS) 2 ] 3 , Cp* 2 U(NMe 2 ) 2 , Y[N(TMS) 2 ] 3 , Cp* 2 Th(CH 2 TMS) 2 , Cp* 2 LaCH(TMS) 2 , Cp* 2 U(CH 2 TMS) 2 , Cp* 2 SmCH(TMS) 2 , and Cp* 2 LuCH(TMS) 2 .
8. A method according to claim 1 wherein the terminal alkyne is of a formula:
≡-R′
wherein R′ is selected from the group consisting of alkyl, aryl, heteroaryl, cycloalkyl, arylalkyl, heteroarylalkyl and cycloalkylalkyl.
9. A method according to claim 8 wherein R′ is selected from the group consisting of C 1 -C 6 -alkyl, aryl, heteroaryl, C 3 -C 7 -cyloalkyl, aryl-C 1 -C 6 -alkyl, heteroaryl-C 1 -C 6 -alkyl and C 3 -C 7 -cyloalkyl-C 1 -C 6 -alkyl.
10. A method according to claim 9 wherein the terminal alkyne is selected from the group consisting of 1-hexyne, ethynylcyclohexane, prop-2-ynylcyclohexane, 1-ethynylcyclohex-1-ene, 3-ethynylpyridine, prop-2-yn-1-amine and ethynylbenzene.
11. A method according to claim 1 wherein the thiol is of a formula:
R″—SH
wherein R″ is selected from the group consisting of alkyl, aryl, heteroaryl, cycloalkyl, arylalkyl, heteroarylalkyl and cycloalkylalkyl.
12. A method according to claim 11 wherein the R″ is selected from the group consisting of C 1 -C 12 -alkyl, aryl, heteroaryl, C 3 -C 7 -cyloalkyl and aryl-C 1 -C 6 -alkyl.
13. A method according to claim 12 wherein the thiol is selected from the group consisting of 1-pentanethiol, 1-dodecanethiol, cyclohexanethiol, 2-methyl-2-butanethiol, benzyl mercaptan, 4-methylbenzyl mercaptan, prop-2-yn-1-amine or thiophenol.
14. A method of preparing a vinyl sulfide comprising treating a thiol of the formula I
R″—SH I
with an alkyne of formula II
≡-R′ II
to afford a corresponding vinyl sulfide of formula III
in the presence of a catalyst selected from the group consisting of;
CGCM 1 R 1 2 , wherein M 1 is selected from an actinide metal and Zr(IV), and R 1 is selected from NMe 2 , NEt 2 and Me;
CGCM 2 R 2 , wherein M 2 is lanthanide metal and R 2 is N(TMS) 2 ;
Cp* 2 M 1 R 3 2 , wherein R 3 is selected from NMe 2 , NEt 2 , Me and CH 2 TMS;
Cp* 2 M 2 R 4 , wherein R 4 is selected from N(TMS) 2 and CH(TMS) 2 ;
Me 2 SiCp″ 2 M 3 R 5 2 , wherein M 3 is an actinide metal, and R 5 is selected from CH 2 TMS and Bn;
M 2 [R 4 ] 3 ;
Cp*M 4 R 6 , wherein M 4 is a Group 4 metal and R 6 is selected from Bn 3 and Cl 2 NMe 2 ; and
M 3 (R 3 ) 4 ,
wherein R′ and R″ are independently selected from the group consisting of alkyl, aryl, heteroaryl, cycloalkyl, arylalkyl, heteroarylalkyl and cycloalkylalkyl.
15. A method according to claim 14 wherein
R′ is selected from the group consisting of C 1 -C 6 -alkyl, aryl, heteroaryl, C 3 -C 7 -cyloalkyl, aryl-C 1 -C 6 -alkyl, heteroaryl-C 1 -C 6 -alkyl and C 3 -C 7 -cyloalkyl-C 1 -C 6 -alkyl; and
R″ is selected from the group consisting of C 1 -C 12 -alkyl, aryl, heteroaryl, C 3 -C 7 -cyloalkyl and aryl-C 1 -C 6 -alkyl.
16. A method according to claim 15 wherein the terminal alkyne is selected from the group consisting of 1-hexyne, ethynylcyclohexane, prop-2-ynylcyclohexane, 1-ethynylcyclohex-1-ene, 3-ethynylpyridine, prop-2-yn-1-amine and ethynylbenzene.
17. A method according to claim 15 wherein the thiol is selected from the group consisting of 1-pentanethiol, 1-dodecanethiol, cyclohexanethiol, 2-methyl-2-butanethiol, benzyl mercaptan, 4-methylbenzyl mercaptan, prop-2-yn-1-amine or thiophenol.
18. A method according to claim 14 wherein the vinyl sulfide is prepared with >90% Markovnikov selectivity.
19. A method according to claim 18 wherein the vinyl sulfide is prepared with no or substantially no double-thiolated side product.
20. A method according to claim 19 wherein the vinyl sulfide is prepared through an alkyne insertion pathway followed by a thiol-mediated protonolysis.
21. A method according to claim 20 wherein the alkyne insertion pathway is turnover-limiting.
22. A method according to claim 14 wherein the catalyst is selected from Cp* 2 SmN(TMS) 2 , Me 2 SiCp″ 2 Th[CH 2 (TMS)] 2 , CGCZrMe 2 , Cp* 2 YCH(TMS) 2 , Cp* 2 YN(TMS) 2 , Me 2 SiCp″ 2 UBn 2 , Cp* 2 ZrMe 2 , CGCSmN(TMS) 2 , CGCU(NMe 2 ) 2 , Cp*ZrBn 3 , La[N(TMS) 2 ] 3 , CGCTh(NMe 2 ) 2 , Zr[NMe 2 ] 4 , Nd[N(TMS) 2 ] 3 , U(NEt 2 ) 4 , Cp*ZrCl 2 NMe 2 , Lu[CH(TMS) 2 ] 3 , Cp* 2 U(NMe 2 ) 2 , Y[N(TMS) 2 ] 3 , Cp* 2 Th(CH 2 TMS) 2 , Cp* 2 LaCH(TMS) 2 , Cp* 2 U(CH 2 TMS) 2 , Cp* 2 SmCH(TMS) 2 , and Cp* 2 LuCH(TMS) 2 .