P-chiral phospholanes and phosphocyclic compounds and their use in asymmetric catalytic reactions

A chiral ligand represented by the formula and its enantiomer:

• 51
• wherein R is selected from the group consisting of:
• alkyl, aryl, substituted alkyl, substituted aryl, hetereoaryl, ferrocenyl, alkoxy and aryloxy;
• and
• wherein n is from 0 to 2.

A catalyst prepared by a process comprising:

• contacting a transition metal salt, or a complex thereof, and a chiral ligand selected from the group consisting of compounds represented by the formula or its enantiomer:
• 60
• wherein X is a divalent group selected from the group consisting of:
• (CR4R5)n, (CR4R5)n-Z-(CR4R5)n and group represented by the formula:
• 61
• wherein each n is independently an integer from 1 to 6;
• wherein each R4 and R5 is independently selected from the group consisting of:
• hydrogen, alkyl, aryl, substituted alkyl, substituted aryl, hetereoaryl, ferrocenyl, halogen, hydroxy, alkoxy, aryloxy, alkylthio, arylthio and amido;
• and
• wherein Z is selected from the group consisting of:
• O, S, —COO—, —CO—, O—(CR4R5)n—O, CH2 (C6H4), CH2 (Ar), CH2(hetereoaryl), alkenyl, CH2(alkenyl), C5H3N, divalent aryl, 2,2′-divalent-1,1′-biphenyl, SiR′2, PR′ and NR6 wherein each of R′ and R6 is independently selected from the group consisting of:
• hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, hydroxy, alkoxy, aryloxy, acyl and alkoxycarbonyl;
• wherein R is selected from the group consisting of:
• alkyl, aryl, substituted alkyl, substituted aryl, hetereoaryl, ferrocenyl, alkoxy and aryloxy;
• wherein E is selected from the group consisting of:
• PR′2, PR′R″, o-substituted pyridine, oxazoline, chiral oxazoline, CH2(chiral oxazoline), CR′2(chiral oxazoline), CH2PR′2, CH2(o-substituted pyridine), SiR′3, CR′2OH and a group represented by the formula:
• 62
• wherein Y is selected from the group consisting of:
• (CR4R5)m and (CR4R5)m-Z-(CR4R5)m;
• wherein each m is independently an integer from 0 to 3;
• wherein each R4 and R5 is independently selected from the group consisting of:
• hydrogen, alkyl, aryl, substituted alkyl, substituted aryl, hetereoaryl, ferrocenyl, halogen, hydroxy, alkoxy, aryloxy, alkylthio, arylthio and amido;
• and wherein Z is selected from the group consisting of:
• O, S, —CO—, —COO—, O—(CR4R5)n—O, CH2 (C6H4), CH2 (Ar), CH2(hetereoaryl), alkenyl, CH2(alkenyl), C5H3N, divalent aryl, 2,2′-divalent-1,1′-biphenyl, SiR′2, PR′ and NR6 wherein each of R′ and R6 is independently selected from the group consisting of:
• hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, hydroxy, alkoxy, aryloxy, acyl and alkoxycarbonyl.

A process for preparation of an asymmetric compound comprising:

• contacting a substrate capable of forming an asymmetric product by an asymmetric reaction and a catalyst prepared by a process comprising:
• contacting a transition metal salt, or a complex thereof, and a chiral ligand selected from the group consisting of compounds represented by the formula or its enantiomer:
• 63
• wherein X is a divalent group selected from the group consisting of:
• (CR4R5)n, (CR4R5)n-Z-(CR4R5)n and group represented by the formula:
• 64
• wherein each n is independently an integer from 1 to 6;
• wherein each R4 and R5 is independently selected from the group consisting of:
• hydrogen, alkyl, aryl, substituted alkyl, substituted aryl, hetereoaryl, ferrocenyl, halogen, hydroxy, alkoxy, aryloxy, alkylthio, arylthio and amido;
• and
• wherein Z is selected from the group consisting of:
• O, S, —COO—, —CO—, O—(CR4R5)n—O, CH2 (C6H4), CH2 (Ar), CH2(hetereoaryl), alkenyl, CH2(alkenyl), C5H3N, divalent aryl, 2,2′-divalent-1,1′-biphenyl, SiR′2, PR′ and NR6 wherein each of R′ and R6 is independently selected from the group consisting of:
• hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, hydroxy, alkoxy, aryloxy, acyl and alkoxycarbonyl;
• wherein R is selected from the group consisting of:
• alkyl, aryl, substituted alkyl, substituted aryl, hetereoaryl, ferrocenyl, alkoxy and aryloxy;
• wherein E is selected from the group consisting of:
• PR′2, PR′R″, o-substituted pyridine, oxazoline, chiral oxazoline, CH2(chiral oxazoline), CR′2(chiral oxazoline), CH2PR′2, CH2(o-substituted pyridine), SiR′3, CR′2OH and a-group represented by the formula:
• 65
• wherein Y is selected from the group consisting of:
• (CR4R5)m and (CR4R5)m-Z-(CR4R5)m;
• wherein each m is independently an integer from 0 to 3;
• wherein each R4 and R5 is independently selected from the group consisting of:
• hydrogen, alkyl, aryl, substituted alkyl, substituted aryl, hetereoaryl, ferrocenyl, halogen, hydroxy, alkoxy, aryloxy, alkylthio, arylthio and amido;
• and wherein Z is selected from the group consisting of:
• O, S, —CO—, —COO—, O—(CR4R5)n—O, CH2 (C6H4), CH2 (Ar), CH2(hetereoaryl), alkenyl, CH2(alkenyl), C5H3N, divalent aryl, 2,2′-divalent-1,1′-biphenyl, SiR′2, PR′ and NR6 wherein each of R′ and R6 is independently selected from the group consisting of:
• hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, hydroxy, alkoxy, aryloxy, acyl and alkoxycarbonyl.

A process for preparing (1S, 1S′, 2R, 2R′)-1,1′-di-alkyl-[2,2′]-diphospholanyl comprising the steps of:

• asymmetrically deprotonating a 1-alkyl-phospholane-1-sulfide with n-butyllithium/(−)-sparteine in a solvent to produce an anion of said 1-alkyl-phospholane-1-sulfide;
• contacting said anion of said 1-alkyl-phospholane-1-sulfide and CuCl2 to oxidatively couple said anion of said 1-alkyl-phospholane-1-sulfide and produce a reaction mixture comprising (1R, 1R′, 2R, 2R′)-1,1′-di-alkyl-[2,2′]-diphospholanyl-1,1′-disulfide;
• recrystallizing said (1R, 1R′, 2R, 2R′)-1,1′-di-alkyl-[2,2′]-diphospholanyl-1,1′-disulfide from said reaction mixture;
• and
• contacting said (1R, 1R′, 2R, 2R′)-1,1′-di-alkyl-[2,2′]-diphospholanyl-1,1′-disulfide and hexachlorodisilane in a solvent to produce (1S, 1S′, 2R, 2R′)-1,1′-di-alkyl-[2,2′]-diphospholanyl.