Science of Synthesis

Collier, S. J., Science of Synthesis, (2007) 20, 1616.

Thiocarboxylic acids are soft nucleophiles and undergo 1,4-addition with Michael acceptors to give the S-esters ‌51‌, often in good yields (‌Scheme 20‌).[‌121‌,‌150‌–‌155‌] Acetylene-1,2-di­carboxylate diesters undergo double Michael additions with thioacetic acid to give dialkyl 2,3-bis(acetyl­sulfanyl) succinates in low yields.[‌156‌] Treatment of a thiocarboxylate salt with a Michael acceptor bearing a leaving group in the β-position gives the corresponding S-vinyl thiocarboxylate.[‌157‌] Asymmetric conjugate additions are also possible. For example, the conjugate addition of thioacetic acid or thiobenzoic acid to chiral (2-methylacryloyl)oxazolidinones (e.g., ‌52‌) proceeds with high diastereoselectivity in the absence of a catalyst. However, poor diastereoselectivities are observed in the presence of titanium(IV) chloride.[‌158‌] When both a primary alkyl bromide and a β,β-disubstituted α,β-unsaturated ester group are present in the same molecule, reaction with sodium thioacetate occurs selectively at the alkyl bromide.[‌126‌]

‌Meeeee 88‌ Meeeeeeeeeeeee Meee M-Meeeee ee Meeeeeee Meeeeeeee ee Meeeeeeeeeeeee Meeee[‌88‌,‌888‌,‌888‌,‌888‌]

‌Meeeeeeeeee 88‌

M8	M+	M	Meeeeeeeee	Meeee (%)	Mee
Me			M8M, eeeeee	88	[‌888‌]
Me			MeM, MMM	88	[‌888‌]
Me			MM8Me8, 88°M, 88 e	88e	[‌888‌]
Me			MM8Me8, 88°M, 88 e	88e	[‌888‌]
(MM8)8MMM8	eeeeeeeeeee	Me	eeee	88	[‌88‌]

e Meeee α/β 88:8.

e Meeee α/β 88:8.

Meeeeeeeeeeeee eeeee eee eeee eeeeeee eeeeeeee eeeeeeeee eeee eeee eeeeeee eeeee eeeeeee ee eeeeeeeeeeeee eeeeeeeeee ee ee eee eeeeeeee ee eeee-eeeeeee eeeeeeeeee ee eeee M-eeeee eeeeeeeeeeeeeeee;[‌888‌–‌888‌] eeee eeeeeeee ee eeee eeeeeeeee eee eeeeeeeee ee Meeeee–Meee, Mee. 8, e 888 eee Mee. M 8/8, e 888. Mee eeeeeee, eeeeeeeeeeeeeeeeee eeeee eeeeeee eeeeeeee eeeeeeeee eeee eeeeeeeeeee ee eeee M-eeeeeeeeee eeeeeeeeeeeeeeeeeeee.[‌88‌] Meeeeeeee, eeeeeeeeeeeeee eeeee eee eee eeeeee eeeeeee,[‌888‌,‌888‌] eee ee eee eeee ee eeeeeeeeee eeee eee eee-8-eee, e 8:8 eeeeeee ee (M)- eee (M)-M-eee-8-eeee eeeeeeeeeeee ee eeeeeeee ee eeeeeeeeeeee eeeee.[‌888‌] Me e eeeeeee eeeeeeee, eee eeeeeeee ee eeeeeeeeeeeee eeeeeeee ee eeeeeee eeeee M-(β-eeeeeeeeee) eeeeeeeeeeeeeeee ee eeee eeeeee.[‌8‌] Meee eeee eeeeeeeeeee eeeeee eee Meeeeee eeeeeeee eeeeee eee eeeeeee ee eee eeee eeeeeeee, ee ee eee eeee ee eeeeeee eeeeeee, eee eeee ee eee eeeeeeee eeeeeeee eee ee eeeeeeeeee ee eeeeeee eeeeeeeee ee eee eeeeeeee eeeeeeeeee. Me eee eeeeeeee ee e eeeeeeeee eeee, Meeeeee eeeeeeee eeeeee, eeeeeee eeeee eeeeeeeeeeeee eeeeeeeeee, eeeeeeeee eeeeeeee eeeeee eee eeeeeeeeeee eeeeee eeeeee eeee ee eeeeeeee; eee eeee eeeeeeeeeee, eee Meeeee–Meee, Mee. 8, e 888 eee Mee. M 8/8, e 888.

Meeeee eeeeeeeeeeee, eeeee eee eeee ee eeeeeeeeee ee eee(eeeeeeeeeeeeee eeee M-eeeeee) eeeeee ee e eeeeeeeee eeee [e.e., M8M(M)MMM8MM(M)M8], eee ee eeeeeeee ee eee eeeeeeee eeeeeee eeeeeeeeeeeeee eeeee eee eeeeeeeee;[‌888‌,‌888‌] eee eeee eeeeeeeeeee, eee Meeeee–Meee, Mee. M 8/8, e 888. Meeeeeeeeeeee, eee eeee-eeeeeeee eeeeeeeeeeeeeeeeee ee eeeeeeeeeeeeee eeeee, eeeeee eeeee eee eeeeeeeee eeeeee ee eeeeeeeeee, eee eeee ee eeee.[‌888‌] Meee eeeeeeeeeeeeeeeeee(eeeeee M-eeee), Meeee eeee eeeeeeeee eeeeeeeeeeee eeee 8-eeeeeeeeeeeeeeeeeee eeeee eee eeeeeeeeeeeee 8,8-eeeeeeee.[‌888‌] Meeee eeeeeeeeeeeee ee eeeee eee ee eee eeeeee eeeee ee eeeeeeee eee ee eeeeeeee ee eee eeeeeeeee ee eeeeeeeeeeeee eeee eeeeeeeeeeeeee eeeee eee eeeeeeeeeeee ee eee eeeeeeee ee eeeeeeeee eeeeeee ee 8-eeeeeeeeeeeeeee eeee ee eeee(MM) eeeeee, eee eeee eeeeee eeeee eee eeee, eee eeeeeeeeeeeee eee eeeeeeee ee eeeeeeeee eeeeeeeeeeeee.[‌888‌,‌888‌]

Meeeeeeeeeee Meeeeeeee

Meeeee Meeeeeeeeeeeee Meee M-Meeeee ‌88‌ [M8 = Me, Me; M8 = (M)-8-Meeeee-8-eee-8-(8-eee-8-eeeeeeeeeeeeeeee-8-ee)eeeeee]; Meeeeee Meeeeeeee:[‌888‌]

M8M(M)MM (M8 = Me, Me; 8 eeee) eee eeeee ee e eeeeeee eeee ee (8M)-8-(8-eeeeeeeeeeeeee)-8-eeeeeeeeeeeeeeee-8-eee (‌88‌; 8.888 e, 8 eeee) ee eee MM8Me8 (88 eM) ee 88°M. Mee eeeeeee eee eeeeeee eeeee eee eeeeeeee eeeeeeee eee eeeeeeee (~88 e), eee eeee eeeeee eeee eee. ee Me8MM8 eee eeeeeeeee eeee Me8M. Mee eeeeeeee eeeeeeee eeee eeeeee eeee 88% ee MeMM eee eeeee, eeeee (MeMM8), eeeeeeee, eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeeeeeee ee eeeee eeeeeeeeeeeeee (eeeeee eee, MeMMe/eeeeee 8:8); eeeee (M8 = Me): 88% (α/β 88:8); eeeee (M8 = Me): 88% (α/β 88:8).

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) 8, 888.
• 8.Meeeee-Meee, (8888) M 8-8, 888.
• 8.Meeeee-Meee, (8888) M 88e, 8888.