6572-99-2

Upstream product

• 4549-31-9 1,7-dibromoheptane 
• 175603-35-7 thiacyclo-oct-4-ene 
• 3070-53-9 1,6-heptadiene 
• 173777-19-0 6-heptenyl thioacetate 

Relevant academic research and scientific papers

Molecular Asymmetry in trans-Thiacycloalkenes. 2. Barriers to Interconversion of Diastereomeric Conformers of 2-Substituted Nine- to Eleven-Membered (E)-Thiacycloalk-4-enes

trans-Thiacycloalk-4-enes of ring size 9 to 11 carrying a substituent (CH3 or COOCH3) at C2 were synthetized.These species have two elements of chirality (a plane and a center) and exist as diastereomeric pairs which may interconvert via a conformational process (180 deg revolution of the ? plane inside out the ring).The energy barrier for this process has been measured by dynamic 13C NMR and found to be 16.4, 10.7, and 8.3 (or 7.0) kcal/mol for the 9-, 10-, and 11-membered-ring compound, respectively, lower than those for their carbocyclic analogues.The lower barriers may arise from the heteroatom across the ring, which, unlike the corresponding carbon in the homocyclic counterpart, carries no ligand and allows for less steric compression in the transition state.

A kinetic investigation, supported by theoretical calculations, of steric and ring strain effects on the oxidation of sulfides and sulfoxides by dimethyldioxirane in acetone

The oxidations of alkyl 4-nitrophenyl, and dialkyl, sulfides and sulfoxides by dimethyldioxirane in acetone occur by concerted mechanisms but the sulfides respond differently from the sulfoxides to variation in the alkyl group. The reactions of the sulfides are inhibited by the steric effects of alkyl groups and these predominate over their inductive effects. By contrast, the reactions of these limited sets of sulfoxides are insensitive to alkyl steric effects but there is an indication of steric acceleration when a broader set of sulfoxides is considered. This behaviour is rationalised in terms of the differences in dipolar charge and its solvation between the ground state and transition state for the two types of substrate. The oxidations of cyclic sulfides and sulfoxides also exhibit contrasting behaviour. The reactivity of the sulfides is insensitive to ring strain but is explicable in frontier orbital terms whereas that of the sulfoxides is partly dependent upon the change in ring strain between reactant and product on oxidation, a difference rationalised in terms of the relative positions of the transition states in the reaction coordinates of the two oxidations. The reactivity of 4-, 5- and 6-membered cyclic sulfoxides is also dependent on a ring-size related property of the transition state. Calculations at the B3-LYP/6-31G* level of density functional theory on both ground states and transition states, including simulation of solvation by acetone, strongly support the mechanistic conclusions reached in this and earlier work.

Low pressure hydrogenation of unsaturated sulphides with homogeneous and heterogeneous ruthenium catalysts

Ru2O·nH2O and [Ru3O(AcO)6(H2O)3]+AcO- were examined for catalytic activity in the hydrogenation of a series of unsaturated sulphides under heterogeneous and homogeneous conditions, respectively. By the appropriate combination of these two methodologies, a number of saturated sulphides could be synthesized in satisfactory to good yields, thus minimizing side reactions.

REGIOSELECTIVITY OF RADICAL CYCLIZATION OF UNSATURATED ORGANOSILICON THIOLS

Regiochemistry of radical cyclizations of isomeric dimethylsila-substituted 5-hexene-1-thiols (1 and 2) and 6-heptene-1-thiols (5 and 6) has been studied.It has been found that the ring closure of alkenylthiyl radicals having a vinyl group at silicon is a

The macrocyclization reaction of terminal dibromoalkanes with sulfide on alumina. The use of a solid support as an alternative to the high dilution technique

The reaction of a series of terminal dibromoalkanes with S-2 on Al2O3 has been examined. The use of a solid support for the macrocyclization represents a viable alternate procedure to the more traditional high dilution technique in solution. The cyclization also occur with thioacetamide on unactivated alumina.